Patent
US 10,522,363SYSTEMS AND METHODS FOR PERFORATION AND OHMIC CONTACT FORMATION FOR GAN EPITAXIAL LIFT-OFF USING AN ETCH STOP LAYER
Christopher Youtsey
MicroLink Devices, Inc.·US
Copyright © 2026 Matter42. All rights reserved.
Patent
Atlas literature
Patent
US 10,522,363Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 schematically illustrates a stackup 100 for a GaN- based device structure. In some embodiments, the stackup 100 for the device structure includes one or …
FIG. 2. The perforation pattern is then transferred into the device layers 110 using a vertical etch as shown in
FIG. 3. Then, the release layer 315 can be etched away using a photoenhanced lateral wet etch environment as illustrated above in
FIG. 4. For both photoelectrochemical enhanced (PEC) wet etches, an external Pt cathode was connected to the topside metal contact. After the lateral etch was …
FIG. 5 schematically illustrates the device layers 110 and the perforated support layer 130 separated from the substrate 125 after etching of the release …
FIG. 6A. The system 200 provides a photoenhanced wet etching environment for photoenhanced etching of the stackup 100 in accordance with some embodiments …
FIG. 7 illustrates the at least one LED source 240, circuit board 242, and heat sink 244 according to an example embodiment described herein. In some …
FIG. 8 illustrates relative spectra obtained from an exemplary light emitting diode source 240 when operated at power levels of 10 %, 50 %, and 100 % of …
FIG. 9 is an image of a profilometry scan within the perforated region of a substrate, without an etch stop layer, after epitaxial lift-off.
FIG. 10 is an image of a profilometry scan within the perforated region of a substrate, with an etch stop layer, after epitaxial lift-off.
FIG. 11 shows three AFM images measured across a 2-inch bulk GaN wafer after epitaxial growth. The variation of miscut on the bulk GaN is likely the primary …
FIG. 12. Very sharp interfaces were obtained, and no misfit dislocations were observed, suggesting no relaxation of the epitaxial films, consistent with RSM …
FIG. 13 shows a sequence of optical images recorded through the transparent backside of a bulk GaN wafer during the ELO lateral etch process. In the first …
FIG. 14 are of a 1-cm 2 GaN ELO foil that has been released from a bulk GaN substrate. The images show the backside, nitrogen face of the GaN foil supported by …
FIG. 15 shows SEM images of a similar GaN structure lifted off from a sapphire substrate. The low-magnification image at left shows the cross perforations and …
FIG. 16B schematically depicts the example Schottky device structure after ELO and attachment to a carrier wafer in accordance with some embodiments.
FIG. 17A is an optical image of the example Schottky device structures on a substrate in accordance with some embodiments.
FIG. 18. Well-behaved diodes were observed both before and after ELO, with a 90 mV/decade slope under forward bias, corresponding to an ideality factor of n = …
FIG. 19 schematically shows a model for a possible mechanism for this behavior. It has been well-established that dislocations contribute to leakage current in …
FIG. 20 is an image of resulting GaN device layers after 4 inch wafer-scale ELO from a sapphire substrate using systems and methods described in some …
FIG. 21 is an image of the resulting substrate-free GaN device layers of
FIG. 22 illustrates GaN ELO from 2-inch bulk GaN. Other Embodiments Other embodiments involve deep photoenhanced wet etching of bulk GaN substrates. The …
FIG. 23C. In some embodiments, the feature is a cross- shaped feature etched into the semiconductor device. The cross-shaped feature was etched to a depth of …
FIG. 24.
FIG. 25 is an electron microscope image from a plan view of the perforation feature of
FIG. 26 illustrates measured photocurrent in systems 200 under different etchant concentration and stirring conditions according to various embodiments …
FIG. 27.
FIG. 28 is an electron microscope image of a perspective view of the etched GaN substrate of
FIG. 29.
FIG. 30 is an electron microscope image of a perspective view of the etch GaN substrate of
FIG. 31 is an SEM image of perforations formed in device layers grown on a bulk GaN substrate using systems and methods described in some embodiments of the …
FIG. 32 schematically depicts a III -nitride compound material stack including a highly doped contact layer for forming a III -nitride compound device using an …
FIG. 33 schematically depicts a device 300' resulting from an ELO process performed on the I II -nitride compound material stack 300 followed by formation of …
FIG. 34 illustrates a flowchart for a method 2000 for forming a GaN-based device free of a substrate. The method 2000 includes forming a release layer 315 on or …
FIG. 35 is a graph of I-V curves for an example transmission line measurement (TLM) structure in accordance with some embodiments.
FIG. 36, the measured specific contact resistance (normalized to area) was about 5 E-3 ohm-cm 2 (5x10-3 ohm-cm 2). FIG s. 37 and 38 show I-V curves and measured …
FIG. 37. FIG s. 39A-C are images from etching of a stackup including an etch stop layer where the etch stop layer was etched completely through most areas …
FIG. 38 is a graph of measured resistance values for the example TLM structure whose I-V curves are depicted in
FIG. 39E is 100 A. In this case, about 1 micron of the GaN layer remained at the end of the process. Experiments with other compositions, other thickness and …
FIG. 40E is an image of a profilometry scan within the perforated region of the layers on the substrate of FIG s. 40A-C after epitaxial lift-off. FIG s. 41A-C …
FIG. 41D is an image of a profilometry scan within the perforated region of the layers on the substrate of FIG s. 41A-C after epitaxial lift-off. DETAILED …
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
1-43. Canceled
Canceled
A method for forming a GaN-based device or an A i N-based device free of a substrate, the method comprising: providing a device structure comprising: a substrate having a first surface and a second surface facing away from the first surface, wherein the substrate comprises GaN or A i N or a layer comprising GaN or A l N is disposed on the first surface of the substrate; an etch stop layer formed over the first surface of the substrate, the etch stop layer having a first bandgap energy level; a release layer formed on the etch stop layer, the release layer having a second bandgap energy level, the second bandgap energy level lower than the first bandgap energy level; one or more device layers formed on the release layer to form the GaN-based device or the A l N-based device; and a perforated support layer formed on one of the one or more device layers forming an outermost layer of the structure; removing portions of the release layer and of the one or more device layers underlying perforations in the perforated support layer, the removing comprising exposing the device structure to a photoenhanced vertical etch environment to vertically etch portions of the release layer and of at least one of the one or more device layers underlying the perforations in the support layer; and Preliminary Amendment and Response to Notice to File Missing Parts exposing the device structure to a photoenhanced lateral wet etch environment to laterally etch the release layer, the photoenhanced lateral wet etch environment impinging photons having an energy level greater than or equal to that of the second bandgap energy level of the release layer and lower than that of the first bandgap energy level of the etch stop layer, thereby removing the release layer from between the etch stop layer and the one or more device layers and separating the substrate from the one or more device layers and the perforated support layer. Currently amended
The method of claim 44, wherein the support layer includes a metal layer having perforations, and wherein the perforations of the metal layer are configured to facilitate vertical etching of the release layer. Currently amended
The method of claim 44, further comprising forming a plurality of perforations in the one or more device layers by etching through the perforations in the support layer for vertical etching of the release layer at multiple locations corresponding to the perforations simultaneously. Currently amended
The method of claim 44, wherein the device is a GaN-based device; and w herein the release layer comprises InGaN. Currently amended
The method of claim 44, wherein the release layer has a thickness between 10 nm and 200 nm. Currently amended
The method of claim 44, wherein the device is a GaN-based device; and wherein at least one of the one or more device layers comprises GaN or InGaN. Currently amended
The method of claim 44, wherein the etch stop layer comprises AlGaN or Al I nGaN. Currently amended
The method of claim 44, wherein the substrate has a diameter corresponding to a 2-inch to 8-inch wafer, and wherein the etching of the release layer to separate the contact layer and the one or more device layers from the substrate occurs on a 2-inch to 8-inch wafer size scale. Currently amended
The method of claim 44, wherein the etch stop layer has a slow etch rate relative to an etch rate of the release layer for the photoenhanced wet etching and the etch stop layer is configured to reduce etching of the substrate during the photoenhanced vertical wet etching. Currently amended
The method of claim 44, wherein the photoenhanced vertical wet etch environment includes impinging photons on the release layer having an energy level greater than that of the second bandgap energy level of the release layer and lower than that of the first bandgap energy level of the etch stop layer. Currently amended
The method of claim 44, wherein exposing the device structure to the photoenhanced vertical etch environment includes illuminating the perforated support layer with [[a]] one or more UV light emitting diode (LED) light sources. Currently amended
The method of claim 44, wherein exposing the device structure to the photoenhanced lateral etch environment includes illuminating the second surface of the substrate with [[a]] one or more filtered UV light emitting diode (LED) light sources. Currently amended
The method of claim 44, wherein the substrate comprises GaN. Currently amended
The method of claim 44, wherein the substrate comprises A l N and at least one of the one or more device layers comprises AlGaN. New
The method of claim 44, wherein providing the device structure comprises: providing the substrate having the first surface and the second surface facing away from the first surface, wherein the substrate comprises GaN or A l N or a layer comprising GaN or A l N is disposed on the first surface of the substrate; forming the etch stop layer over the first surface of the substrate; forming the release layer on the etch stop layer; forming the one or more device layers on the release layer to form the GaN-based device or the A l N-based device; and forming the perforated support layer on one of the one or more device layers to form the outermost layer of a stackup. New
The method of claim 44, further comprising covering the second surface of the substrate with a transparent chemically protective layer prior to exposing the stackup to the photoenhanced vertical wet etch environment. New
The method of claim 44, further comprising: removing the etch stop layer from the substrate and polishing the substrate; and reusing the substrate to form a second GaN-based device free from a substrate. New
The method of claim 44, further comprising forming a contact layer having a doping concentration of between 1x10 8 cm- 3 and 5x10 2 cm⁻³ over the release layer. New
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51-52. Canceled
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54-55. Preliminary Amendment and Response to Notice to File Missing Parts Canceled
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59-64. Canceled
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Canceled
Preliminary Amendment and Response to Notice to File Missing Parts Canceled
72-78. Canceled
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A structure for forming a GaN-based device or an A l N-based device using epitaxial lift-off, the structure comprising: a substrate having a first surface and a second surface facing away from the first surface, wherein the substrate comprises GaN or A l N or a layer comprising GaN or A l N is disposed on the first surface of the substrate; an etch stop layer formed over the first surface of the substrate, the etch stop layer having a first bandgap energy; a release layer formed on the etch stop layer, the release layer having a second bandgap energy, wherein the second bandgap energy is lower than the first bandgap energy; one or more device layers formed over the release layer to form the GaN-based device or the Al N-based device; and Preliminary Amendment and Response to Notice to File Missing Parts a perforated support layer formed on one of the one or more device layers to form an outermost layer of the structure. Currently amended
83-170. Canceled
Canceled
Layer stacks claimed or described, ordered top of device to substrate.
GaN-based or AlN-based epitaxial lift-off device structure
Materials described outside the worked examples.
GaN
etch stop layer
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 4. For both photoelectrochemical enhanced (PEC) wet etches, an external Pt cathode was connected to the topside metal contact. After the lateral etch was …
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
specific contact resistance of ohmic contact on contact layer | — | contact layer |
Thickness | 10–200 nm |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 10,522,363Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 schematically illustrates a stackup 100 for a GaN- based device structure. In some embodiments, the stackup 100 for the device structure includes one or …
FIG. 2. The perforation pattern is then transferred into the device layers 110 using a vertical etch as shown in
FIG. 3. Then, the release layer 315 can be etched away using a photoenhanced lateral wet etch environment as illustrated above in
FIG. 4. For both photoelectrochemical enhanced (PEC) wet etches, an external Pt cathode was connected to the topside metal contact. After the lateral etch was …
FIG. 5 schematically illustrates the device layers 110 and the perforated support layer 130 separated from the substrate 125 after etching of the release …
FIG. 6A. The system 200 provides a photoenhanced wet etching environment for photoenhanced etching of the stackup 100 in accordance with some embodiments …
FIG. 7 illustrates the at least one LED source 240, circuit board 242, and heat sink 244 according to an example embodiment described herein. In some …
FIG. 8 illustrates relative spectra obtained from an exemplary light emitting diode source 240 when operated at power levels of 10 %, 50 %, and 100 % of …
FIG. 9 is an image of a profilometry scan within the perforated region of a substrate, without an etch stop layer, after epitaxial lift-off.
FIG. 10 is an image of a profilometry scan within the perforated region of a substrate, with an etch stop layer, after epitaxial lift-off.
FIG. 11 shows three AFM images measured across a 2-inch bulk GaN wafer after epitaxial growth. The variation of miscut on the bulk GaN is likely the primary …
FIG. 12. Very sharp interfaces were obtained, and no misfit dislocations were observed, suggesting no relaxation of the epitaxial films, consistent with RSM …
FIG. 13 shows a sequence of optical images recorded through the transparent backside of a bulk GaN wafer during the ELO lateral etch process. In the first …
FIG. 14 are of a 1-cm 2 GaN ELO foil that has been released from a bulk GaN substrate. The images show the backside, nitrogen face of the GaN foil supported by …
FIG. 15 shows SEM images of a similar GaN structure lifted off from a sapphire substrate. The low-magnification image at left shows the cross perforations and …
FIG. 16B schematically depicts the example Schottky device structure after ELO and attachment to a carrier wafer in accordance with some embodiments.
FIG. 17A is an optical image of the example Schottky device structures on a substrate in accordance with some embodiments.
FIG. 18. Well-behaved diodes were observed both before and after ELO, with a 90 mV/decade slope under forward bias, corresponding to an ideality factor of n = …
FIG. 19 schematically shows a model for a possible mechanism for this behavior. It has been well-established that dislocations contribute to leakage current in …
FIG. 20 is an image of resulting GaN device layers after 4 inch wafer-scale ELO from a sapphire substrate using systems and methods described in some …
FIG. 21 is an image of the resulting substrate-free GaN device layers of
FIG. 22 illustrates GaN ELO from 2-inch bulk GaN. Other Embodiments Other embodiments involve deep photoenhanced wet etching of bulk GaN substrates. The …
FIG. 23C. In some embodiments, the feature is a cross- shaped feature etched into the semiconductor device. The cross-shaped feature was etched to a depth of …
FIG. 24.
FIG. 25 is an electron microscope image from a plan view of the perforation feature of
FIG. 26 illustrates measured photocurrent in systems 200 under different etchant concentration and stirring conditions according to various embodiments …
FIG. 27.
FIG. 28 is an electron microscope image of a perspective view of the etched GaN substrate of
FIG. 29.
FIG. 30 is an electron microscope image of a perspective view of the etch GaN substrate of
FIG. 31 is an SEM image of perforations formed in device layers grown on a bulk GaN substrate using systems and methods described in some embodiments of the …
FIG. 32 schematically depicts a III -nitride compound material stack including a highly doped contact layer for forming a III -nitride compound device using an …
FIG. 33 schematically depicts a device 300' resulting from an ELO process performed on the I II -nitride compound material stack 300 followed by formation of …
FIG. 34 illustrates a flowchart for a method 2000 for forming a GaN-based device free of a substrate. The method 2000 includes forming a release layer 315 on or …
FIG. 35 is a graph of I-V curves for an example transmission line measurement (TLM) structure in accordance with some embodiments.
FIG. 36, the measured specific contact resistance (normalized to area) was about 5 E-3 ohm-cm 2 (5x10-3 ohm-cm 2). FIG s. 37 and 38 show I-V curves and measured …
FIG. 37. FIG s. 39A-C are images from etching of a stackup including an etch stop layer where the etch stop layer was etched completely through most areas …
FIG. 38 is a graph of measured resistance values for the example TLM structure whose I-V curves are depicted in
FIG. 39E is 100 A. In this case, about 1 micron of the GaN layer remained at the end of the process. Experiments with other compositions, other thickness and …
FIG. 40E is an image of a profilometry scan within the perforated region of the layers on the substrate of FIG s. 40A-C after epitaxial lift-off. FIG s. 41A-C …
FIG. 41D is an image of a profilometry scan within the perforated region of the layers on the substrate of FIG s. 41A-C after epitaxial lift-off. DETAILED …
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
1-43. Canceled
Canceled
A method for forming a GaN-based device or an A i N-based device free of a substrate, the method comprising: providing a device structure comprising: a substrate having a first surface and a second surface facing away from the first surface, wherein the substrate comprises GaN or A i N or a layer comprising GaN or A l N is disposed on the first surface of the substrate; an etch stop layer formed over the first surface of the substrate, the etch stop layer having a first bandgap energy level; a release layer formed on the etch stop layer, the release layer having a second bandgap energy level, the second bandgap energy level lower than the first bandgap energy level; one or more device layers formed on the release layer to form the GaN-based device or the A l N-based device; and a perforated support layer formed on one of the one or more device layers forming an outermost layer of the structure; removing portions of the release layer and of the one or more device layers underlying perforations in the perforated support layer, the removing comprising exposing the device structure to a photoenhanced vertical etch environment to vertically etch portions of the release layer and of at least one of the one or more device layers underlying the perforations in the support layer; and Preliminary Amendment and Response to Notice to File Missing Parts exposing the device structure to a photoenhanced lateral wet etch environment to laterally etch the release layer, the photoenhanced lateral wet etch environment impinging photons having an energy level greater than or equal to that of the second bandgap energy level of the release layer and lower than that of the first bandgap energy level of the etch stop layer, thereby removing the release layer from between the etch stop layer and the one or more device layers and separating the substrate from the one or more device layers and the perforated support layer. Currently amended
The method of claim 44, wherein the support layer includes a metal layer having perforations, and wherein the perforations of the metal layer are configured to facilitate vertical etching of the release layer. Currently amended
The method of claim 44, further comprising forming a plurality of perforations in the one or more device layers by etching through the perforations in the support layer for vertical etching of the release layer at multiple locations corresponding to the perforations simultaneously. Currently amended
The method of claim 44, wherein the device is a GaN-based device; and w herein the release layer comprises InGaN. Currently amended
The method of claim 44, wherein the release layer has a thickness between 10 nm and 200 nm. Currently amended
The method of claim 44, wherein the device is a GaN-based device; and wherein at least one of the one or more device layers comprises GaN or InGaN. Currently amended
The method of claim 44, wherein the etch stop layer comprises AlGaN or Al I nGaN. Currently amended
The method of claim 44, wherein the substrate has a diameter corresponding to a 2-inch to 8-inch wafer, and wherein the etching of the release layer to separate the contact layer and the one or more device layers from the substrate occurs on a 2-inch to 8-inch wafer size scale. Currently amended
The method of claim 44, wherein the etch stop layer has a slow etch rate relative to an etch rate of the release layer for the photoenhanced wet etching and the etch stop layer is configured to reduce etching of the substrate during the photoenhanced vertical wet etching. Currently amended
The method of claim 44, wherein the photoenhanced vertical wet etch environment includes impinging photons on the release layer having an energy level greater than that of the second bandgap energy level of the release layer and lower than that of the first bandgap energy level of the etch stop layer. Currently amended
The method of claim 44, wherein exposing the device structure to the photoenhanced vertical etch environment includes illuminating the perforated support layer with [[a]] one or more UV light emitting diode (LED) light sources. Currently amended
The method of claim 44, wherein exposing the device structure to the photoenhanced lateral etch environment includes illuminating the second surface of the substrate with [[a]] one or more filtered UV light emitting diode (LED) light sources. Currently amended
The method of claim 44, wherein the substrate comprises GaN. Currently amended
The method of claim 44, wherein the substrate comprises A l N and at least one of the one or more device layers comprises AlGaN. New
The method of claim 44, wherein providing the device structure comprises: providing the substrate having the first surface and the second surface facing away from the first surface, wherein the substrate comprises GaN or A l N or a layer comprising GaN or A l N is disposed on the first surface of the substrate; forming the etch stop layer over the first surface of the substrate; forming the release layer on the etch stop layer; forming the one or more device layers on the release layer to form the GaN-based device or the A l N-based device; and forming the perforated support layer on one of the one or more device layers to form the outermost layer of a stackup. New
The method of claim 44, further comprising covering the second surface of the substrate with a transparent chemically protective layer prior to exposing the stackup to the photoenhanced vertical wet etch environment. New
The method of claim 44, further comprising: removing the etch stop layer from the substrate and polishing the substrate; and reusing the substrate to form a second GaN-based device free from a substrate. New
The method of claim 44, further comprising forming a contact layer having a doping concentration of between 1x10 8 cm- 3 and 5x10 2 cm⁻³ over the release layer. New
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51-52. Canceled
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54-55. Preliminary Amendment and Response to Notice to File Missing Parts Canceled
Canceled
59-64. Canceled
Canceled
Canceled
Preliminary Amendment and Response to Notice to File Missing Parts Canceled
72-78. Canceled
Canceled
Canceled
A structure for forming a GaN-based device or an A l N-based device using epitaxial lift-off, the structure comprising: a substrate having a first surface and a second surface facing away from the first surface, wherein the substrate comprises GaN or A l N or a layer comprising GaN or A l N is disposed on the first surface of the substrate; an etch stop layer formed over the first surface of the substrate, the etch stop layer having a first bandgap energy; a release layer formed on the etch stop layer, the release layer having a second bandgap energy, wherein the second bandgap energy is lower than the first bandgap energy; one or more device layers formed over the release layer to form the GaN-based device or the Al N-based device; and Preliminary Amendment and Response to Notice to File Missing Parts a perforated support layer formed on one of the one or more device layers to form an outermost layer of the structure. Currently amended
83-170. Canceled
Canceled
Layer stacks claimed or described, ordered top of device to substrate.
GaN-based or AlN-based epitaxial lift-off device structure
Materials described outside the worked examples.
GaN
etch stop layer
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 4. For both photoelectrochemical enhanced (PEC) wet etches, an external Pt cathode was connected to the topside metal contact. After the lateral etch was …
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
specific contact resistance of ohmic contact on contact layer | — | contact layer |
Thickness | 10–200 nm |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 10,522,363Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 schematically illustrates a stackup 100 for a GaN- based device structure. In some embodiments, the stackup 100 for the device structure includes one or …
FIG. 2. The perforation pattern is then transferred into the device layers 110 using a vertical etch as shown in
FIG. 3. Then, the release layer 315 can be etched away using a photoenhanced lateral wet etch environment as illustrated above in
FIG. 4. For both photoelectrochemical enhanced (PEC) wet etches, an external Pt cathode was connected to the topside metal contact. After the lateral etch was …
FIG. 5 schematically illustrates the device layers 110 and the perforated support layer 130 separated from the substrate 125 after etching of the release …
FIG. 6A. The system 200 provides a photoenhanced wet etching environment for photoenhanced etching of the stackup 100 in accordance with some embodiments …
FIG. 7 illustrates the at least one LED source 240, circuit board 242, and heat sink 244 according to an example embodiment described herein. In some …
FIG. 8 illustrates relative spectra obtained from an exemplary light emitting diode source 240 when operated at power levels of 10 %, 50 %, and 100 % of …
FIG. 9 is an image of a profilometry scan within the perforated region of a substrate, without an etch stop layer, after epitaxial lift-off.
FIG. 10 is an image of a profilometry scan within the perforated region of a substrate, with an etch stop layer, after epitaxial lift-off.
FIG. 11 shows three AFM images measured across a 2-inch bulk GaN wafer after epitaxial growth. The variation of miscut on the bulk GaN is likely the primary …
FIG. 12. Very sharp interfaces were obtained, and no misfit dislocations were observed, suggesting no relaxation of the epitaxial films, consistent with RSM …
FIG. 13 shows a sequence of optical images recorded through the transparent backside of a bulk GaN wafer during the ELO lateral etch process. In the first …
FIG. 14 are of a 1-cm 2 GaN ELO foil that has been released from a bulk GaN substrate. The images show the backside, nitrogen face of the GaN foil supported by …
FIG. 15 shows SEM images of a similar GaN structure lifted off from a sapphire substrate. The low-magnification image at left shows the cross perforations and …
FIG. 16B schematically depicts the example Schottky device structure after ELO and attachment to a carrier wafer in accordance with some embodiments.
FIG. 17A is an optical image of the example Schottky device structures on a substrate in accordance with some embodiments.
FIG. 18. Well-behaved diodes were observed both before and after ELO, with a 90 mV/decade slope under forward bias, corresponding to an ideality factor of n = …
FIG. 19 schematically shows a model for a possible mechanism for this behavior. It has been well-established that dislocations contribute to leakage current in …
FIG. 20 is an image of resulting GaN device layers after 4 inch wafer-scale ELO from a sapphire substrate using systems and methods described in some …
FIG. 21 is an image of the resulting substrate-free GaN device layers of
FIG. 22 illustrates GaN ELO from 2-inch bulk GaN. Other Embodiments Other embodiments involve deep photoenhanced wet etching of bulk GaN substrates. The …
FIG. 23C. In some embodiments, the feature is a cross- shaped feature etched into the semiconductor device. The cross-shaped feature was etched to a depth of …
FIG. 24.
FIG. 25 is an electron microscope image from a plan view of the perforation feature of
FIG. 26 illustrates measured photocurrent in systems 200 under different etchant concentration and stirring conditions according to various embodiments …
FIG. 27.
FIG. 28 is an electron microscope image of a perspective view of the etched GaN substrate of
FIG. 29.
FIG. 30 is an electron microscope image of a perspective view of the etch GaN substrate of
FIG. 31 is an SEM image of perforations formed in device layers grown on a bulk GaN substrate using systems and methods described in some embodiments of the …
FIG. 32 schematically depicts a III -nitride compound material stack including a highly doped contact layer for forming a III -nitride compound device using an …
FIG. 33 schematically depicts a device 300' resulting from an ELO process performed on the I II -nitride compound material stack 300 followed by formation of …
FIG. 34 illustrates a flowchart for a method 2000 for forming a GaN-based device free of a substrate. The method 2000 includes forming a release layer 315 on or …
FIG. 35 is a graph of I-V curves for an example transmission line measurement (TLM) structure in accordance with some embodiments.
FIG. 36, the measured specific contact resistance (normalized to area) was about 5 E-3 ohm-cm 2 (5x10-3 ohm-cm 2). FIG s. 37 and 38 show I-V curves and measured …
FIG. 37. FIG s. 39A-C are images from etching of a stackup including an etch stop layer where the etch stop layer was etched completely through most areas …
FIG. 38 is a graph of measured resistance values for the example TLM structure whose I-V curves are depicted in
FIG. 39E is 100 A. In this case, about 1 micron of the GaN layer remained at the end of the process. Experiments with other compositions, other thickness and …
FIG. 40E is an image of a profilometry scan within the perforated region of the layers on the substrate of FIG s. 40A-C after epitaxial lift-off. FIG s. 41A-C …
FIG. 41D is an image of a profilometry scan within the perforated region of the layers on the substrate of FIG s. 41A-C after epitaxial lift-off. DETAILED …
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
1-43. Canceled
Canceled
A method for forming a GaN-based device or an A i N-based device free of a substrate, the method comprising: providing a device structure comprising: a substrate having a first surface and a second surface facing away from the first surface, wherein the substrate comprises GaN or A i N or a layer comprising GaN or A l N is disposed on the first surface of the substrate; an etch stop layer formed over the first surface of the substrate, the etch stop layer having a first bandgap energy level; a release layer formed on the etch stop layer, the release layer having a second bandgap energy level, the second bandgap energy level lower than the first bandgap energy level; one or more device layers formed on the release layer to form the GaN-based device or the A l N-based device; and a perforated support layer formed on one of the one or more device layers forming an outermost layer of the structure; removing portions of the release layer and of the one or more device layers underlying perforations in the perforated support layer, the removing comprising exposing the device structure to a photoenhanced vertical etch environment to vertically etch portions of the release layer and of at least one of the one or more device layers underlying the perforations in the support layer; and Preliminary Amendment and Response to Notice to File Missing Parts exposing the device structure to a photoenhanced lateral wet etch environment to laterally etch the release layer, the photoenhanced lateral wet etch environment impinging photons having an energy level greater than or equal to that of the second bandgap energy level of the release layer and lower than that of the first bandgap energy level of the etch stop layer, thereby removing the release layer from between the etch stop layer and the one or more device layers and separating the substrate from the one or more device layers and the perforated support layer. Currently amended
The method of claim 44, wherein the support layer includes a metal layer having perforations, and wherein the perforations of the metal layer are configured to facilitate vertical etching of the release layer. Currently amended
The method of claim 44, further comprising forming a plurality of perforations in the one or more device layers by etching through the perforations in the support layer for vertical etching of the release layer at multiple locations corresponding to the perforations simultaneously. Currently amended
The method of claim 44, wherein the device is a GaN-based device; and w herein the release layer comprises InGaN. Currently amended
The method of claim 44, wherein the release layer has a thickness between 10 nm and 200 nm. Currently amended
The method of claim 44, wherein the device is a GaN-based device; and wherein at least one of the one or more device layers comprises GaN or InGaN. Currently amended
The method of claim 44, wherein the etch stop layer comprises AlGaN or Al I nGaN. Currently amended
The method of claim 44, wherein the substrate has a diameter corresponding to a 2-inch to 8-inch wafer, and wherein the etching of the release layer to separate the contact layer and the one or more device layers from the substrate occurs on a 2-inch to 8-inch wafer size scale. Currently amended
The method of claim 44, wherein the etch stop layer has a slow etch rate relative to an etch rate of the release layer for the photoenhanced wet etching and the etch stop layer is configured to reduce etching of the substrate during the photoenhanced vertical wet etching. Currently amended
The method of claim 44, wherein the photoenhanced vertical wet etch environment includes impinging photons on the release layer having an energy level greater than that of the second bandgap energy level of the release layer and lower than that of the first bandgap energy level of the etch stop layer. Currently amended
The method of claim 44, wherein exposing the device structure to the photoenhanced vertical etch environment includes illuminating the perforated support layer with [[a]] one or more UV light emitting diode (LED) light sources. Currently amended
The method of claim 44, wherein exposing the device structure to the photoenhanced lateral etch environment includes illuminating the second surface of the substrate with [[a]] one or more filtered UV light emitting diode (LED) light sources. Currently amended
The method of claim 44, wherein the substrate comprises GaN. Currently amended
The method of claim 44, wherein the substrate comprises A l N and at least one of the one or more device layers comprises AlGaN. New
The method of claim 44, wherein providing the device structure comprises: providing the substrate having the first surface and the second surface facing away from the first surface, wherein the substrate comprises GaN or A l N or a layer comprising GaN or A l N is disposed on the first surface of the substrate; forming the etch stop layer over the first surface of the substrate; forming the release layer on the etch stop layer; forming the one or more device layers on the release layer to form the GaN-based device or the A l N-based device; and forming the perforated support layer on one of the one or more device layers to form the outermost layer of a stackup. New
The method of claim 44, further comprising covering the second surface of the substrate with a transparent chemically protective layer prior to exposing the stackup to the photoenhanced vertical wet etch environment. New
The method of claim 44, further comprising: removing the etch stop layer from the substrate and polishing the substrate; and reusing the substrate to form a second GaN-based device free from a substrate. New
The method of claim 44, further comprising forming a contact layer having a doping concentration of between 1x10 8 cm- 3 and 5x10 2 cm⁻³ over the release layer. New
45-46.. Canceled
Canceled
51-52. Canceled
Canceled
54-55. Preliminary Amendment and Response to Notice to File Missing Parts Canceled
Canceled
59-64. Canceled
Canceled
Canceled
Preliminary Amendment and Response to Notice to File Missing Parts Canceled
72-78. Canceled
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A structure for forming a GaN-based device or an A l N-based device using epitaxial lift-off, the structure comprising: a substrate having a first surface and a second surface facing away from the first surface, wherein the substrate comprises GaN or A l N or a layer comprising GaN or A l N is disposed on the first surface of the substrate; an etch stop layer formed over the first surface of the substrate, the etch stop layer having a first bandgap energy; a release layer formed on the etch stop layer, the release layer having a second bandgap energy, wherein the second bandgap energy is lower than the first bandgap energy; one or more device layers formed over the release layer to form the GaN-based device or the Al N-based device; and Preliminary Amendment and Response to Notice to File Missing Parts a perforated support layer formed on one of the one or more device layers to form an outermost layer of the structure. Currently amended
83-170. Canceled
Canceled
Layer stacks claimed or described, ordered top of device to substrate.
GaN-based or AlN-based epitaxial lift-off device structure
Materials described outside the worked examples.
GaN
etch stop layer
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 4. For both photoelectrochemical enhanced (PEC) wet etches, an external Pt cathode was connected to the topside metal contact. After the lateral etch was …
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
specific contact resistance of ohmic contact on contact layer | — | contact layer |
Thickness | 10–200 nm |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 10,522,363Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 schematically illustrates a stackup 100 for a GaN- based device structure. In some embodiments, the stackup 100 for the device structure includes one or …
FIG. 2. The perforation pattern is then transferred into the device layers 110 using a vertical etch as shown in
FIG. 3. Then, the release layer 315 can be etched away using a photoenhanced lateral wet etch environment as illustrated above in
FIG. 4. For both photoelectrochemical enhanced (PEC) wet etches, an external Pt cathode was connected to the topside metal contact. After the lateral etch was …
FIG. 5 schematically illustrates the device layers 110 and the perforated support layer 130 separated from the substrate 125 after etching of the release …
FIG. 6A. The system 200 provides a photoenhanced wet etching environment for photoenhanced etching of the stackup 100 in accordance with some embodiments …
FIG. 7 illustrates the at least one LED source 240, circuit board 242, and heat sink 244 according to an example embodiment described herein. In some …
FIG. 8 illustrates relative spectra obtained from an exemplary light emitting diode source 240 when operated at power levels of 10 %, 50 %, and 100 % of …
FIG. 9 is an image of a profilometry scan within the perforated region of a substrate, without an etch stop layer, after epitaxial lift-off.
FIG. 10 is an image of a profilometry scan within the perforated region of a substrate, with an etch stop layer, after epitaxial lift-off.
FIG. 11 shows three AFM images measured across a 2-inch bulk GaN wafer after epitaxial growth. The variation of miscut on the bulk GaN is likely the primary …
FIG. 12. Very sharp interfaces were obtained, and no misfit dislocations were observed, suggesting no relaxation of the epitaxial films, consistent with RSM …
FIG. 13 shows a sequence of optical images recorded through the transparent backside of a bulk GaN wafer during the ELO lateral etch process. In the first …
FIG. 14 are of a 1-cm 2 GaN ELO foil that has been released from a bulk GaN substrate. The images show the backside, nitrogen face of the GaN foil supported by …
FIG. 15 shows SEM images of a similar GaN structure lifted off from a sapphire substrate. The low-magnification image at left shows the cross perforations and …
FIG. 16B schematically depicts the example Schottky device structure after ELO and attachment to a carrier wafer in accordance with some embodiments.
FIG. 17A is an optical image of the example Schottky device structures on a substrate in accordance with some embodiments.
FIG. 18. Well-behaved diodes were observed both before and after ELO, with a 90 mV/decade slope under forward bias, corresponding to an ideality factor of n = …
FIG. 19 schematically shows a model for a possible mechanism for this behavior. It has been well-established that dislocations contribute to leakage current in …
FIG. 20 is an image of resulting GaN device layers after 4 inch wafer-scale ELO from a sapphire substrate using systems and methods described in some …
FIG. 21 is an image of the resulting substrate-free GaN device layers of
FIG. 22 illustrates GaN ELO from 2-inch bulk GaN. Other Embodiments Other embodiments involve deep photoenhanced wet etching of bulk GaN substrates. The …
FIG. 23C. In some embodiments, the feature is a cross- shaped feature etched into the semiconductor device. The cross-shaped feature was etched to a depth of …
FIG. 24.
FIG. 25 is an electron microscope image from a plan view of the perforation feature of
FIG. 26 illustrates measured photocurrent in systems 200 under different etchant concentration and stirring conditions according to various embodiments …
FIG. 27.
FIG. 28 is an electron microscope image of a perspective view of the etched GaN substrate of
FIG. 29.
FIG. 30 is an electron microscope image of a perspective view of the etch GaN substrate of
FIG. 31 is an SEM image of perforations formed in device layers grown on a bulk GaN substrate using systems and methods described in some embodiments of the …
FIG. 32 schematically depicts a III -nitride compound material stack including a highly doped contact layer for forming a III -nitride compound device using an …
FIG. 33 schematically depicts a device 300' resulting from an ELO process performed on the I II -nitride compound material stack 300 followed by formation of …
FIG. 34 illustrates a flowchart for a method 2000 for forming a GaN-based device free of a substrate. The method 2000 includes forming a release layer 315 on or …
FIG. 35 is a graph of I-V curves for an example transmission line measurement (TLM) structure in accordance with some embodiments.
FIG. 36, the measured specific contact resistance (normalized to area) was about 5 E-3 ohm-cm 2 (5x10-3 ohm-cm 2). FIG s. 37 and 38 show I-V curves and measured …
FIG. 37. FIG s. 39A-C are images from etching of a stackup including an etch stop layer where the etch stop layer was etched completely through most areas …
FIG. 38 is a graph of measured resistance values for the example TLM structure whose I-V curves are depicted in
FIG. 39E is 100 A. In this case, about 1 micron of the GaN layer remained at the end of the process. Experiments with other compositions, other thickness and …
FIG. 40E is an image of a profilometry scan within the perforated region of the layers on the substrate of FIG s. 40A-C after epitaxial lift-off. FIG s. 41A-C …
FIG. 41D is an image of a profilometry scan within the perforated region of the layers on the substrate of FIG s. 41A-C after epitaxial lift-off. DETAILED …
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
1-43. Canceled
Canceled
A method for forming a GaN-based device or an A i N-based device free of a substrate, the method comprising: providing a device structure comprising: a substrate having a first surface and a second surface facing away from the first surface, wherein the substrate comprises GaN or A i N or a layer comprising GaN or A l N is disposed on the first surface of the substrate; an etch stop layer formed over the first surface of the substrate, the etch stop layer having a first bandgap energy level; a release layer formed on the etch stop layer, the release layer having a second bandgap energy level, the second bandgap energy level lower than the first bandgap energy level; one or more device layers formed on the release layer to form the GaN-based device or the A l N-based device; and a perforated support layer formed on one of the one or more device layers forming an outermost layer of the structure; removing portions of the release layer and of the one or more device layers underlying perforations in the perforated support layer, the removing comprising exposing the device structure to a photoenhanced vertical etch environment to vertically etch portions of the release layer and of at least one of the one or more device layers underlying the perforations in the support layer; and Preliminary Amendment and Response to Notice to File Missing Parts exposing the device structure to a photoenhanced lateral wet etch environment to laterally etch the release layer, the photoenhanced lateral wet etch environment impinging photons having an energy level greater than or equal to that of the second bandgap energy level of the release layer and lower than that of the first bandgap energy level of the etch stop layer, thereby removing the release layer from between the etch stop layer and the one or more device layers and separating the substrate from the one or more device layers and the perforated support layer. Currently amended
The method of claim 44, wherein the support layer includes a metal layer having perforations, and wherein the perforations of the metal layer are configured to facilitate vertical etching of the release layer. Currently amended
The method of claim 44, further comprising forming a plurality of perforations in the one or more device layers by etching through the perforations in the support layer for vertical etching of the release layer at multiple locations corresponding to the perforations simultaneously. Currently amended
The method of claim 44, wherein the device is a GaN-based device; and w herein the release layer comprises InGaN. Currently amended
The method of claim 44, wherein the release layer has a thickness between 10 nm and 200 nm. Currently amended
The method of claim 44, wherein the device is a GaN-based device; and wherein at least one of the one or more device layers comprises GaN or InGaN. Currently amended
The method of claim 44, wherein the etch stop layer comprises AlGaN or Al I nGaN. Currently amended
The method of claim 44, wherein the substrate has a diameter corresponding to a 2-inch to 8-inch wafer, and wherein the etching of the release layer to separate the contact layer and the one or more device layers from the substrate occurs on a 2-inch to 8-inch wafer size scale. Currently amended
The method of claim 44, wherein the etch stop layer has a slow etch rate relative to an etch rate of the release layer for the photoenhanced wet etching and the etch stop layer is configured to reduce etching of the substrate during the photoenhanced vertical wet etching. Currently amended
The method of claim 44, wherein the photoenhanced vertical wet etch environment includes impinging photons on the release layer having an energy level greater than that of the second bandgap energy level of the release layer and lower than that of the first bandgap energy level of the etch stop layer. Currently amended
The method of claim 44, wherein exposing the device structure to the photoenhanced vertical etch environment includes illuminating the perforated support layer with [[a]] one or more UV light emitting diode (LED) light sources. Currently amended
The method of claim 44, wherein exposing the device structure to the photoenhanced lateral etch environment includes illuminating the second surface of the substrate with [[a]] one or more filtered UV light emitting diode (LED) light sources. Currently amended
The method of claim 44, wherein the substrate comprises GaN. Currently amended
The method of claim 44, wherein the substrate comprises A l N and at least one of the one or more device layers comprises AlGaN. New
The method of claim 44, wherein providing the device structure comprises: providing the substrate having the first surface and the second surface facing away from the first surface, wherein the substrate comprises GaN or A l N or a layer comprising GaN or A l N is disposed on the first surface of the substrate; forming the etch stop layer over the first surface of the substrate; forming the release layer on the etch stop layer; forming the one or more device layers on the release layer to form the GaN-based device or the A l N-based device; and forming the perforated support layer on one of the one or more device layers to form the outermost layer of a stackup. New
The method of claim 44, further comprising covering the second surface of the substrate with a transparent chemically protective layer prior to exposing the stackup to the photoenhanced vertical wet etch environment. New
The method of claim 44, further comprising: removing the etch stop layer from the substrate and polishing the substrate; and reusing the substrate to form a second GaN-based device free from a substrate. New
The method of claim 44, further comprising forming a contact layer having a doping concentration of between 1x10 8 cm- 3 and 5x10 2 cm⁻³ over the release layer. New
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51-52. Canceled
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54-55. Preliminary Amendment and Response to Notice to File Missing Parts Canceled
Canceled
59-64. Canceled
Canceled
Canceled
Preliminary Amendment and Response to Notice to File Missing Parts Canceled
72-78. Canceled
Canceled
Canceled
A structure for forming a GaN-based device or an A l N-based device using epitaxial lift-off, the structure comprising: a substrate having a first surface and a second surface facing away from the first surface, wherein the substrate comprises GaN or A l N or a layer comprising GaN or A l N is disposed on the first surface of the substrate; an etch stop layer formed over the first surface of the substrate, the etch stop layer having a first bandgap energy; a release layer formed on the etch stop layer, the release layer having a second bandgap energy, wherein the second bandgap energy is lower than the first bandgap energy; one or more device layers formed over the release layer to form the GaN-based device or the Al N-based device; and Preliminary Amendment and Response to Notice to File Missing Parts a perforated support layer formed on one of the one or more device layers to form an outermost layer of the structure. Currently amended
83-170. Canceled
Canceled
Layer stacks claimed or described, ordered top of device to substrate.
GaN-based or AlN-based epitaxial lift-off device structure
Materials described outside the worked examples.
GaN
etch stop layer
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 4. For both photoelectrochemical enhanced (PEC) wet etches, an external Pt cathode was connected to the topside metal contact. After the lateral etch was …
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
specific contact resistance of ohmic contact on contact layer | — | contact layer |
Thickness | 10–200 nm |
Related documents with shared materials, methods, properties, or citations.
release layer
AlN
metal support layer
InGaN
AlGaN
AlInGaN
transparent chemically protective layer
contact layer
n-type GaN doped with Si or Ge
GaN:Si/Ge
FIG. 8 illustrates relative spectra obtained from an exemplary light emitting diode source 240 when operated at power levels of 10 %, 50 %, and 100 % of …
FIG. 11 shows three AFM images measured across a 2-inch bulk GaN wafer after epitaxial growth. The variation of miscut on the bulk GaN is likely the primary …
FIG. 12. Very sharp interfaces were obtained, and no misfit dislocations were observed, suggesting no relaxation of the epitaxial films, consistent with RSM …
FIG. 15 shows SEM images of a similar GaN structure lifted off from a sapphire substrate. The low-magnification image at left shows the cross perforations and …
FIG. 18. Well-behaved diodes were observed both before and after ELO, with a 90 mV/decade slope under forward bias, corresponding to an ideality factor of n = …
FIG. 18. Well-behaved diodes were observed both before and after ELO, with a 90 mV/decade slope under forward bias, corresponding to an ideality factor of n = …
FIG. 23C. In some embodiments, the feature is a cross- shaped feature etched into the semiconductor device. The cross-shaped feature was etched to a depth of …
FIG. 26 illustrates measured photocurrent in systems 200 under different etchant concentration and stirring conditions according to various embodiments …
FIG. 31 is an SEM image of perforations formed in device layers grown on a bulk GaN substrate using systems and methods described in some embodiments of the …
FIG. 33 schematically depicts a device 300' resulting from an ELO process performed on the I II -nitride compound material stack 300 followed by formation of …
FIG. 33 schematically depicts a device 300' resulting from an ELO process performed on the I II -nitride compound material stack 300 followed by formation of …
FIG. 35 is a graph of I-V curves for an example transmission line measurement (TLM) structure in accordance with some embodiments.
FIG. 35 is a graph of I-V curves for an example transmission line measurement (TLM) structure in accordance with some embodiments.
FIG. 36, the measured specific contact resistance (normalized to area) was about 5 E-3 ohm-cm 2 (5x10-3 ohm-cm 2). FIG s. 37 and 38 show I-V curves and measured …
FIG. 36, the measured specific contact resistance (normalized to area) was about 5 E-3 ohm-cm 2 (5x10-3 ohm-cm 2). FIG s. 37 and 38 show I-V curves and measured …
FIG. 37. FIG s. 39A-C are images from etching of a stackup including an etch stop layer where the etch stop layer was etched completely through most areas …
FIG. 37. FIG s. 39A-C are images from etching of a stackup including an etch stop layer where the etch stop layer was etched completely through most areas …
FIG. 38 is a graph of measured resistance values for the example TLM structure whose I-V curves are depicted in
FIG. 38 is a graph of measured resistance values for the example TLM structure whose I-V curves are depicted in
FIG. 39E is 100 A. In this case, about 1 micron of the GaN layer remained at the end of the process. Experiments with other compositions, other thickness and …
| — |
Thickness | 40–110 nm | — |
Thickness | 60–100 nm | — |
Thickness | 5–20 cm | — |
Thickness | 6–20 cm | — |
Thickness | 0.15–0.35 nm | — |
Thickness | 20–50 nm | — |
Thickness | 30–35 nm | — |
Thickness | 1–50 mm | — |
Thickness | 1–10 mm | — |
Thickness | 0.5–5 mm | — |
— | 50–300 W | — |
Thickness | 10–500 µm | — |
— | 2–20 W | — |
— | 2–100 W | — |
— | 2–6 W | — |
— | 2–4 W | — |
Thickness | 367–370 nm | — |
Thickness | ≤ 110 nm | — |
Thickness | ≤ 365 nm | — |
Duration | ≤ 2 hours | — |
Thickness | ≥ 1 mm | — |
Thickness | ≥ 10 µm | — |
Thickness | 100–2000 nm | — |
release layer
AlN
metal support layer
InGaN
AlGaN
AlInGaN
transparent chemically protective layer
contact layer
n-type GaN doped with Si or Ge
GaN:Si/Ge
FIG. 8 illustrates relative spectra obtained from an exemplary light emitting diode source 240 when operated at power levels of 10 %, 50 %, and 100 % of …
FIG. 11 shows three AFM images measured across a 2-inch bulk GaN wafer after epitaxial growth. The variation of miscut on the bulk GaN is likely the primary …
FIG. 12. Very sharp interfaces were obtained, and no misfit dislocations were observed, suggesting no relaxation of the epitaxial films, consistent with RSM …
FIG. 15 shows SEM images of a similar GaN structure lifted off from a sapphire substrate. The low-magnification image at left shows the cross perforations and …
FIG. 18. Well-behaved diodes were observed both before and after ELO, with a 90 mV/decade slope under forward bias, corresponding to an ideality factor of n = …
FIG. 18. Well-behaved diodes were observed both before and after ELO, with a 90 mV/decade slope under forward bias, corresponding to an ideality factor of n = …
FIG. 23C. In some embodiments, the feature is a cross- shaped feature etched into the semiconductor device. The cross-shaped feature was etched to a depth of …
FIG. 26 illustrates measured photocurrent in systems 200 under different etchant concentration and stirring conditions according to various embodiments …
FIG. 31 is an SEM image of perforations formed in device layers grown on a bulk GaN substrate using systems and methods described in some embodiments of the …
FIG. 33 schematically depicts a device 300' resulting from an ELO process performed on the I II -nitride compound material stack 300 followed by formation of …
FIG. 33 schematically depicts a device 300' resulting from an ELO process performed on the I II -nitride compound material stack 300 followed by formation of …
FIG. 35 is a graph of I-V curves for an example transmission line measurement (TLM) structure in accordance with some embodiments.
FIG. 35 is a graph of I-V curves for an example transmission line measurement (TLM) structure in accordance with some embodiments.
FIG. 36, the measured specific contact resistance (normalized to area) was about 5 E-3 ohm-cm 2 (5x10-3 ohm-cm 2). FIG s. 37 and 38 show I-V curves and measured …
FIG. 36, the measured specific contact resistance (normalized to area) was about 5 E-3 ohm-cm 2 (5x10-3 ohm-cm 2). FIG s. 37 and 38 show I-V curves and measured …
FIG. 37. FIG s. 39A-C are images from etching of a stackup including an etch stop layer where the etch stop layer was etched completely through most areas …
FIG. 37. FIG s. 39A-C are images from etching of a stackup including an etch stop layer where the etch stop layer was etched completely through most areas …
FIG. 38 is a graph of measured resistance values for the example TLM structure whose I-V curves are depicted in
FIG. 38 is a graph of measured resistance values for the example TLM structure whose I-V curves are depicted in
FIG. 39E is 100 A. In this case, about 1 micron of the GaN layer remained at the end of the process. Experiments with other compositions, other thickness and …
| — |
Thickness | 40–110 nm | — |
Thickness | 60–100 nm | — |
Thickness | 5–20 cm | — |
Thickness | 6–20 cm | — |
Thickness | 0.15–0.35 nm | — |
Thickness | 20–50 nm | — |
Thickness | 30–35 nm | — |
Thickness | 1–50 mm | — |
Thickness | 1–10 mm | — |
Thickness | 0.5–5 mm | — |
— | 50–300 W | — |
Thickness | 10–500 µm | — |
— | 2–20 W | — |
— | 2–100 W | — |
— | 2–6 W | — |
— | 2–4 W | — |
Thickness | 367–370 nm | — |
Thickness | ≤ 110 nm | — |
Thickness | ≤ 365 nm | — |
Duration | ≤ 2 hours | — |
Thickness | ≥ 1 mm | — |
Thickness | ≥ 10 µm | — |
Thickness | 100–2000 nm | — |
release layer
AlN
metal support layer
InGaN
AlGaN
AlInGaN
transparent chemically protective layer
contact layer
n-type GaN doped with Si or Ge
GaN:Si/Ge
FIG. 8 illustrates relative spectra obtained from an exemplary light emitting diode source 240 when operated at power levels of 10 %, 50 %, and 100 % of …
FIG. 11 shows three AFM images measured across a 2-inch bulk GaN wafer after epitaxial growth. The variation of miscut on the bulk GaN is likely the primary …
FIG. 12. Very sharp interfaces were obtained, and no misfit dislocations were observed, suggesting no relaxation of the epitaxial films, consistent with RSM …
FIG. 15 shows SEM images of a similar GaN structure lifted off from a sapphire substrate. The low-magnification image at left shows the cross perforations and …
FIG. 18. Well-behaved diodes were observed both before and after ELO, with a 90 mV/decade slope under forward bias, corresponding to an ideality factor of n = …
FIG. 18. Well-behaved diodes were observed both before and after ELO, with a 90 mV/decade slope under forward bias, corresponding to an ideality factor of n = …
FIG. 23C. In some embodiments, the feature is a cross- shaped feature etched into the semiconductor device. The cross-shaped feature was etched to a depth of …
FIG. 26 illustrates measured photocurrent in systems 200 under different etchant concentration and stirring conditions according to various embodiments …
FIG. 31 is an SEM image of perforations formed in device layers grown on a bulk GaN substrate using systems and methods described in some embodiments of the …
FIG. 33 schematically depicts a device 300' resulting from an ELO process performed on the I II -nitride compound material stack 300 followed by formation of …
FIG. 33 schematically depicts a device 300' resulting from an ELO process performed on the I II -nitride compound material stack 300 followed by formation of …
FIG. 35 is a graph of I-V curves for an example transmission line measurement (TLM) structure in accordance with some embodiments.
FIG. 35 is a graph of I-V curves for an example transmission line measurement (TLM) structure in accordance with some embodiments.
FIG. 36, the measured specific contact resistance (normalized to area) was about 5 E-3 ohm-cm 2 (5x10-3 ohm-cm 2). FIG s. 37 and 38 show I-V curves and measured …
FIG. 36, the measured specific contact resistance (normalized to area) was about 5 E-3 ohm-cm 2 (5x10-3 ohm-cm 2). FIG s. 37 and 38 show I-V curves and measured …
FIG. 37. FIG s. 39A-C are images from etching of a stackup including an etch stop layer where the etch stop layer was etched completely through most areas …
FIG. 37. FIG s. 39A-C are images from etching of a stackup including an etch stop layer where the etch stop layer was etched completely through most areas …
FIG. 38 is a graph of measured resistance values for the example TLM structure whose I-V curves are depicted in
FIG. 38 is a graph of measured resistance values for the example TLM structure whose I-V curves are depicted in
FIG. 39E is 100 A. In this case, about 1 micron of the GaN layer remained at the end of the process. Experiments with other compositions, other thickness and …
| — |
Thickness | 40–110 nm | — |
Thickness | 60–100 nm | — |
Thickness | 5–20 cm | — |
Thickness | 6–20 cm | — |
Thickness | 0.15–0.35 nm | — |
Thickness | 20–50 nm | — |
Thickness | 30–35 nm | — |
Thickness | 1–50 mm | — |
Thickness | 1–10 mm | — |
Thickness | 0.5–5 mm | — |
— | 50–300 W | — |
Thickness | 10–500 µm | — |
— | 2–20 W | — |
— | 2–100 W | — |
— | 2–6 W | — |
— | 2–4 W | — |
Thickness | 367–370 nm | — |
Thickness | ≤ 110 nm | — |
Thickness | ≤ 365 nm | — |
Duration | ≤ 2 hours | — |
Thickness | ≥ 1 mm | — |
Thickness | ≥ 10 µm | — |
Thickness | 100–2000 nm | — |
release layer
AlN
metal support layer
InGaN
AlGaN
AlInGaN
transparent chemically protective layer
contact layer
n-type GaN doped with Si or Ge
GaN:Si/Ge
FIG. 8 illustrates relative spectra obtained from an exemplary light emitting diode source 240 when operated at power levels of 10 %, 50 %, and 100 % of …
FIG. 11 shows three AFM images measured across a 2-inch bulk GaN wafer after epitaxial growth. The variation of miscut on the bulk GaN is likely the primary …
FIG. 12. Very sharp interfaces were obtained, and no misfit dislocations were observed, suggesting no relaxation of the epitaxial films, consistent with RSM …
FIG. 15 shows SEM images of a similar GaN structure lifted off from a sapphire substrate. The low-magnification image at left shows the cross perforations and …
FIG. 18. Well-behaved diodes were observed both before and after ELO, with a 90 mV/decade slope under forward bias, corresponding to an ideality factor of n = …
FIG. 18. Well-behaved diodes were observed both before and after ELO, with a 90 mV/decade slope under forward bias, corresponding to an ideality factor of n = …
FIG. 23C. In some embodiments, the feature is a cross- shaped feature etched into the semiconductor device. The cross-shaped feature was etched to a depth of …
FIG. 26 illustrates measured photocurrent in systems 200 under different etchant concentration and stirring conditions according to various embodiments …
FIG. 31 is an SEM image of perforations formed in device layers grown on a bulk GaN substrate using systems and methods described in some embodiments of the …
FIG. 33 schematically depicts a device 300' resulting from an ELO process performed on the I II -nitride compound material stack 300 followed by formation of …
FIG. 33 schematically depicts a device 300' resulting from an ELO process performed on the I II -nitride compound material stack 300 followed by formation of …
FIG. 35 is a graph of I-V curves for an example transmission line measurement (TLM) structure in accordance with some embodiments.
FIG. 35 is a graph of I-V curves for an example transmission line measurement (TLM) structure in accordance with some embodiments.
FIG. 36, the measured specific contact resistance (normalized to area) was about 5 E-3 ohm-cm 2 (5x10-3 ohm-cm 2). FIG s. 37 and 38 show I-V curves and measured …
FIG. 36, the measured specific contact resistance (normalized to area) was about 5 E-3 ohm-cm 2 (5x10-3 ohm-cm 2). FIG s. 37 and 38 show I-V curves and measured …
FIG. 37. FIG s. 39A-C are images from etching of a stackup including an etch stop layer where the etch stop layer was etched completely through most areas …
FIG. 37. FIG s. 39A-C are images from etching of a stackup including an etch stop layer where the etch stop layer was etched completely through most areas …
FIG. 38 is a graph of measured resistance values for the example TLM structure whose I-V curves are depicted in
FIG. 38 is a graph of measured resistance values for the example TLM structure whose I-V curves are depicted in
FIG. 39E is 100 A. In this case, about 1 micron of the GaN layer remained at the end of the process. Experiments with other compositions, other thickness and …
| — |
Thickness | 40–110 nm | — |
Thickness | 60–100 nm | — |
Thickness | 5–20 cm | — |
Thickness | 6–20 cm | — |
Thickness | 0.15–0.35 nm | — |
Thickness | 20–50 nm | — |
Thickness | 30–35 nm | — |
Thickness | 1–50 mm | — |
Thickness | 1–10 mm | — |
Thickness | 0.5–5 mm | — |
— | 50–300 W | — |
Thickness | 10–500 µm | — |
— | 2–20 W | — |
— | 2–100 W | — |
— | 2–6 W | — |
— | 2–4 W | — |
Thickness | 367–370 nm | — |
Thickness | ≤ 110 nm | — |
Thickness | ≤ 365 nm | — |
Duration | ≤ 2 hours | — |
Thickness | ≥ 1 mm | — |
Thickness | ≥ 10 µm | — |
Thickness | 100–2000 nm | — |