Patent
Atlas literature
Patent
US 8,455,885Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 illustrates a process cha rt in accordance with the present invention, for the growth on sapphire.
FIG. 2A illustrates a process chart in accordance with the present invention, for the 25 growth on silicon carbide.
FIG. 3 illustrates a process chart in accordance with the present invention, for the growth of semi- insulating GaN on sapphire. 30
FIG. 4A illustrates a process chart in accordance with the present invention, for the growth of semi-insulating GaN on silicon carbide substrate.
FIG. 5(b) shows an atomic force microscope 5 (AFM) image of N- face GaN grown by MOC V D on a nitrided sapphire substrate
FIG. 6 shows transmission electron micrographs, under different imaging conditions, of an N-face GaN film grown using the present invention
FIG. 7(b) shows photoluminescence (PL) from MQWs 10 comprising 5 x (3 nm thick In o.1Ga0. 9N/8 nm thick GaN).
FIG. 8 shows X-ray Diffraction (XRD) of N-face nitride MQWs comprising 5 x (4 nm thick In 0.12Gao.ss N/10 nm thick GaN).
FIG. 9 is a graph showing SIMS results of oxygen impurities as a function of temperature. 15
FIG. 10 is a graph showing SIMS results of carbon impurities as a function of temperature.
FIG. 11(a) and 11(b) are graphs of SIMS results of Mg incorporation in an N-face (
FIGS. 12a-12f illustrate optical micrographs of 0.8 micron thick GaN films grown 20 on sapphire substrates in accordance with the present invention.
FIG. 13 illustrates one or more embodiments of the present invention that incorporate growth of additional I II -nitride films.
FIGS. 14A-14C illustrate micrographs of N-polar films grown on various substrates in accordance with one or more embodiments of the present invention. 25
FIGS. 15 A-B illustrate micrographs of the GaN surface showing surface topologies.
FIGS. 16A-B illustrate micrographs of a GaN film produced in one or more embodiments of the present invention.
FIG. 17 illustrates one or more embodiments of the present invention. 30 7
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A device structure, comprising: a substrate having a growth surface, wherein the growth surface has a misorientation angle relative to a miller indexed crystallographic plane [h, i, k, 1] of the substrate, where h, i, k, 1 are miller indices; ~~ro~h ------- --------------- \GNlyro h o-oth surfa cv a-polar---- (I ---iur Nitride ------ a rL; ===i4Ji l ayer on the G a- pol ar G aN la y er -tr- e 1i-±th-w ±-5:r-ftee, w herein the transitio n layer sets an N-polar [000-1] orientation for one or more subsequent layers formed on the transition layer; and one or more N-polar group I II -nitride layers on the transition layer, wherein: the N-po l ar g roup III-n itride la y ers i nc l ude a G aN la y er, the N-polar group I II -nitride layers have the N-polar [000-1] orientation set by the transition layer, and the N-polar group I II -nitride layers have a top surface that is smooth with a root mean square surface roughness of no more than 2 nanometers over an area of at least micrometers by 10 micrometers.
The device structure of claim 1, further comprising a nitride layer on the growth surface and between the substrate and the N-polar group I II -nitride layers, wherein an orientation of the nitride layer is different from an N-polar orientation.
The device structure of claim 1, wherein the substrate is a nitridized misoriented substrate.
The device structure of claim 1, wherein -e lye i" tr a nsition ayer, and an atomic structure of a surface of the transition layer adjacent to the N-polar group I II -nitride layers results in the N-polar group I II -nitride layers, grown on top of the transition layer, having the N-polar [000-1] orientation.
The device structure of claim 1, wherein the N- polar group I II -nitride layers have a threading dislocation density of at most on an order of 109 cm2.
canceled
The device structure of claim 2 1, wherein the transition layer is doped with magnesium.
The device structure of claim 2 1 wherein the miller indices are h =1, i= 0, k = 0 and 1= -1 and the substrate is silicon carbide.
The device structure of claim 2 1, wherein the miller indices are h = 0, i= 0, k = 0 and 1= 1 and the substrate is sapphire.
The device structure of claim 2 1, wherein the miller indices are h =1, k = 1, 1= 1 and the substrate is silicon.
The device structure of claim 2 1, wherein the substrate is (001) Si.
The device structure of claim 2 1, wherein: the N-polar group I II -nitride layers are doped or undoped to form a device structure for an N-face transistor or light emitting device, a surface of the transition layer adjacent to the N-polar group I II -nitride layers results in the N-polar group I II -nitride layers grown on top of the transition layer having the N-polar [000-1] orientation.
The device structure of claim 2 1, wherein a portion of the transition layer adjacent to a first surface of the transition layer is Ga-polar and a portion of the transition layer adjacent to a second surface of the transition layer is N-polar.
The device structure of claim 21, wherein the misorientation angle is between 0.5 and degrees.
canceled
canceled
The device structure of claim [[18]] 1, wherein: at least one of the N-polar group I II -nitride layers includes a channel of the device structure, at least one of the N-polar group I II -nitride layers is a misoriented N-face layer, and the channel is oriented, with respect to a misorientation direction of the misoriented N-face layer.
A method for fabricating an N-polar group I II -nitride device structure, comprising: obtaining a growth surface of a substrate, wherein the growth surface has a misorientation angle relative to a miller indexed crystallographic plane [h, i, k, 1] of the substrate, where h, i, k, 1 are miller indices; formng a--plar Gallium st ridee tGa\) aver Qfl th !m oth s u rface; -4- G&C 30794.311-US-C l forming a t ra n sition layer on the Ga-polar G aN la y er vr ove the grcwh I fa, wherein the transitio n layer sets an N-polar [000-1] orientation for one or more subsequent layers formed on the transition layer; and growing ft" one or more N-polar group I II -nitride l6yef layers on the transition layer, wherein: the N-polar g ro u p III -nit r ide la y ers include a GaN la y er the N-polar group I II -nitride 1ayef-he s la y ers have the N-polar [000-1] orientation set by the tr a nsition layer, and the N-polar group I II -nitride layers have a top surface that is smooth with a root mean square surface roughness of no more than 2 nanometers over an area of at least micrometers by 10 micrometers.
The method of claim 19, foj±comprising doping the spnsitinlayer with magnesium.
A device structure, comprising: a substrate having a growth surface, wherein the growth surface has a misorientation angle relative to a miller indexed crystallographic plane [h, i, k, 1] of the substrate, where h, i, k, 1 are miller indices; and a gr oup I I -N transitio n layer on or above the growth surface, wherein: the g r oup I II -N transition layer sets an N-polar [000-1] orientation for one or more subsequent layers formed on the layer, and a portion of the g rou p III -N transition layer adjacent the growth surface is diff~ciit fi-&m afl N p lar group Iii nirideor Ga-p olar; and one or more N-polar group I II -nitride layers on the group III -N transition layer, wherein the N-polar group I II -nitride layers have the N-polar [000-1] orientation set by the groupIIIN ransitian _ layer.
A device structure, comprising: a substrate comprising sapphire, silicon, or SiC, the substrate having a growth surface, wherein the growth surface has a misorientation angle relative to a miller indexed crystallographic plane of the substrate; a transition layer on the Ga-p olar (G aN layer or ab ove thc gr owth s ur fac e, wherein the transition layer sets an N-polar [000-1] orientation for one or more subsequent layers formed on the transitin _ layer; and one or more N-polar group I II -nitride layers on the transition layer, wherein the one or more N-polar group I II-nitride layers have the N-polar [000-1] orientation set by the transition layer and the one or more N-polar g- rou p III -nitride layers include a G aN layer.
Layer stacks claimed or described, ordered top of device to substrate.
N-polar group III-nitride device structure
N-face HEMT transistor
Materials described outside the worked examples.
misoriented substrate
Ga-polar GaN layer
GaN
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 5(b) shows an atomic force microscope 5 (AFM) image of N- face GaN grown by MOC V D on a nitrided sapphire substrate
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
RMS surface roughness of N-polar group III-nitride top surface, no more than 2 nm over 10x10 µm area | ≤ 2 nm | N-polar group III-nitride layers |
Threading dislocation density of N-polar group III-nitride layers, at most ~10^9 cm^-2 |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 8,455,885Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 illustrates a process cha rt in accordance with the present invention, for the growth on sapphire.
FIG. 2A illustrates a process chart in accordance with the present invention, for the 25 growth on silicon carbide.
FIG. 3 illustrates a process chart in accordance with the present invention, for the growth of semi- insulating GaN on sapphire. 30
FIG. 4A illustrates a process chart in accordance with the present invention, for the growth of semi-insulating GaN on silicon carbide substrate.
FIG. 5(b) shows an atomic force microscope 5 (AFM) image of N- face GaN grown by MOC V D on a nitrided sapphire substrate
FIG. 6 shows transmission electron micrographs, under different imaging conditions, of an N-face GaN film grown using the present invention
FIG. 7(b) shows photoluminescence (PL) from MQWs 10 comprising 5 x (3 nm thick In o.1Ga0. 9N/8 nm thick GaN).
FIG. 8 shows X-ray Diffraction (XRD) of N-face nitride MQWs comprising 5 x (4 nm thick In 0.12Gao.ss N/10 nm thick GaN).
FIG. 9 is a graph showing SIMS results of oxygen impurities as a function of temperature. 15
FIG. 10 is a graph showing SIMS results of carbon impurities as a function of temperature.
FIG. 11(a) and 11(b) are graphs of SIMS results of Mg incorporation in an N-face (
FIGS. 12a-12f illustrate optical micrographs of 0.8 micron thick GaN films grown 20 on sapphire substrates in accordance with the present invention.
FIG. 13 illustrates one or more embodiments of the present invention that incorporate growth of additional I II -nitride films.
FIGS. 14A-14C illustrate micrographs of N-polar films grown on various substrates in accordance with one or more embodiments of the present invention. 25
FIGS. 15 A-B illustrate micrographs of the GaN surface showing surface topologies.
FIGS. 16A-B illustrate micrographs of a GaN film produced in one or more embodiments of the present invention.
FIG. 17 illustrates one or more embodiments of the present invention. 30 7
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A device structure, comprising: a substrate having a growth surface, wherein the growth surface has a misorientation angle relative to a miller indexed crystallographic plane [h, i, k, 1] of the substrate, where h, i, k, 1 are miller indices; ~~ro~h ------- --------------- \GNlyro h o-oth surfa cv a-polar---- (I ---iur Nitride ------ a rL; ===i4Ji l ayer on the G a- pol ar G aN la y er -tr- e 1i-±th-w ±-5:r-ftee, w herein the transitio n layer sets an N-polar [000-1] orientation for one or more subsequent layers formed on the transition layer; and one or more N-polar group I II -nitride layers on the transition layer, wherein: the N-po l ar g roup III-n itride la y ers i nc l ude a G aN la y er, the N-polar group I II -nitride layers have the N-polar [000-1] orientation set by the transition layer, and the N-polar group I II -nitride layers have a top surface that is smooth with a root mean square surface roughness of no more than 2 nanometers over an area of at least micrometers by 10 micrometers.
The device structure of claim 1, further comprising a nitride layer on the growth surface and between the substrate and the N-polar group I II -nitride layers, wherein an orientation of the nitride layer is different from an N-polar orientation.
The device structure of claim 1, wherein the substrate is a nitridized misoriented substrate.
The device structure of claim 1, wherein -e lye i" tr a nsition ayer, and an atomic structure of a surface of the transition layer adjacent to the N-polar group I II -nitride layers results in the N-polar group I II -nitride layers, grown on top of the transition layer, having the N-polar [000-1] orientation.
The device structure of claim 1, wherein the N- polar group I II -nitride layers have a threading dislocation density of at most on an order of 109 cm2.
canceled
The device structure of claim 2 1, wherein the transition layer is doped with magnesium.
The device structure of claim 2 1 wherein the miller indices are h =1, i= 0, k = 0 and 1= -1 and the substrate is silicon carbide.
The device structure of claim 2 1, wherein the miller indices are h = 0, i= 0, k = 0 and 1= 1 and the substrate is sapphire.
The device structure of claim 2 1, wherein the miller indices are h =1, k = 1, 1= 1 and the substrate is silicon.
The device structure of claim 2 1, wherein the substrate is (001) Si.
The device structure of claim 2 1, wherein: the N-polar group I II -nitride layers are doped or undoped to form a device structure for an N-face transistor or light emitting device, a surface of the transition layer adjacent to the N-polar group I II -nitride layers results in the N-polar group I II -nitride layers grown on top of the transition layer having the N-polar [000-1] orientation.
The device structure of claim 2 1, wherein a portion of the transition layer adjacent to a first surface of the transition layer is Ga-polar and a portion of the transition layer adjacent to a second surface of the transition layer is N-polar.
The device structure of claim 21, wherein the misorientation angle is between 0.5 and degrees.
canceled
canceled
The device structure of claim [[18]] 1, wherein: at least one of the N-polar group I II -nitride layers includes a channel of the device structure, at least one of the N-polar group I II -nitride layers is a misoriented N-face layer, and the channel is oriented, with respect to a misorientation direction of the misoriented N-face layer.
A method for fabricating an N-polar group I II -nitride device structure, comprising: obtaining a growth surface of a substrate, wherein the growth surface has a misorientation angle relative to a miller indexed crystallographic plane [h, i, k, 1] of the substrate, where h, i, k, 1 are miller indices; formng a--plar Gallium st ridee tGa\) aver Qfl th !m oth s u rface; -4- G&C 30794.311-US-C l forming a t ra n sition layer on the Ga-polar G aN la y er vr ove the grcwh I fa, wherein the transitio n layer sets an N-polar [000-1] orientation for one or more subsequent layers formed on the transition layer; and growing ft" one or more N-polar group I II -nitride l6yef layers on the transition layer, wherein: the N-polar g ro u p III -nit r ide la y ers include a GaN la y er the N-polar group I II -nitride 1ayef-he s la y ers have the N-polar [000-1] orientation set by the tr a nsition layer, and the N-polar group I II -nitride layers have a top surface that is smooth with a root mean square surface roughness of no more than 2 nanometers over an area of at least micrometers by 10 micrometers.
The method of claim 19, foj±comprising doping the spnsitinlayer with magnesium.
A device structure, comprising: a substrate having a growth surface, wherein the growth surface has a misorientation angle relative to a miller indexed crystallographic plane [h, i, k, 1] of the substrate, where h, i, k, 1 are miller indices; and a gr oup I I -N transitio n layer on or above the growth surface, wherein: the g r oup I II -N transition layer sets an N-polar [000-1] orientation for one or more subsequent layers formed on the layer, and a portion of the g rou p III -N transition layer adjacent the growth surface is diff~ciit fi-&m afl N p lar group Iii nirideor Ga-p olar; and one or more N-polar group I II -nitride layers on the group III -N transition layer, wherein the N-polar group I II -nitride layers have the N-polar [000-1] orientation set by the groupIIIN ransitian _ layer.
A device structure, comprising: a substrate comprising sapphire, silicon, or SiC, the substrate having a growth surface, wherein the growth surface has a misorientation angle relative to a miller indexed crystallographic plane of the substrate; a transition layer on the Ga-p olar (G aN layer or ab ove thc gr owth s ur fac e, wherein the transition layer sets an N-polar [000-1] orientation for one or more subsequent layers formed on the transitin _ layer; and one or more N-polar group I II -nitride layers on the transition layer, wherein the one or more N-polar group I II-nitride layers have the N-polar [000-1] orientation set by the transition layer and the one or more N-polar g- rou p III -nitride layers include a G aN layer.
Layer stacks claimed or described, ordered top of device to substrate.
N-polar group III-nitride device structure
N-face HEMT transistor
Materials described outside the worked examples.
misoriented substrate
Ga-polar GaN layer
GaN
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 5(b) shows an atomic force microscope 5 (AFM) image of N- face GaN grown by MOC V D on a nitrided sapphire substrate
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
RMS surface roughness of N-polar group III-nitride top surface, no more than 2 nm over 10x10 µm area | ≤ 2 nm | N-polar group III-nitride layers |
Threading dislocation density of N-polar group III-nitride layers, at most ~10^9 cm^-2 |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 8,455,885Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 illustrates a process cha rt in accordance with the present invention, for the growth on sapphire.
FIG. 2A illustrates a process chart in accordance with the present invention, for the 25 growth on silicon carbide.
FIG. 3 illustrates a process chart in accordance with the present invention, for the growth of semi- insulating GaN on sapphire. 30
FIG. 4A illustrates a process chart in accordance with the present invention, for the growth of semi-insulating GaN on silicon carbide substrate.
FIG. 5(b) shows an atomic force microscope 5 (AFM) image of N- face GaN grown by MOC V D on a nitrided sapphire substrate
FIG. 6 shows transmission electron micrographs, under different imaging conditions, of an N-face GaN film grown using the present invention
FIG. 7(b) shows photoluminescence (PL) from MQWs 10 comprising 5 x (3 nm thick In o.1Ga0. 9N/8 nm thick GaN).
FIG. 8 shows X-ray Diffraction (XRD) of N-face nitride MQWs comprising 5 x (4 nm thick In 0.12Gao.ss N/10 nm thick GaN).
FIG. 9 is a graph showing SIMS results of oxygen impurities as a function of temperature. 15
FIG. 10 is a graph showing SIMS results of carbon impurities as a function of temperature.
FIG. 11(a) and 11(b) are graphs of SIMS results of Mg incorporation in an N-face (
FIGS. 12a-12f illustrate optical micrographs of 0.8 micron thick GaN films grown 20 on sapphire substrates in accordance with the present invention.
FIG. 13 illustrates one or more embodiments of the present invention that incorporate growth of additional I II -nitride films.
FIGS. 14A-14C illustrate micrographs of N-polar films grown on various substrates in accordance with one or more embodiments of the present invention. 25
FIGS. 15 A-B illustrate micrographs of the GaN surface showing surface topologies.
FIGS. 16A-B illustrate micrographs of a GaN film produced in one or more embodiments of the present invention.
FIG. 17 illustrates one or more embodiments of the present invention. 30 7
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A device structure, comprising: a substrate having a growth surface, wherein the growth surface has a misorientation angle relative to a miller indexed crystallographic plane [h, i, k, 1] of the substrate, where h, i, k, 1 are miller indices; ~~ro~h ------- --------------- \GNlyro h o-oth surfa cv a-polar---- (I ---iur Nitride ------ a rL; ===i4Ji l ayer on the G a- pol ar G aN la y er -tr- e 1i-±th-w ±-5:r-ftee, w herein the transitio n layer sets an N-polar [000-1] orientation for one or more subsequent layers formed on the transition layer; and one or more N-polar group I II -nitride layers on the transition layer, wherein: the N-po l ar g roup III-n itride la y ers i nc l ude a G aN la y er, the N-polar group I II -nitride layers have the N-polar [000-1] orientation set by the transition layer, and the N-polar group I II -nitride layers have a top surface that is smooth with a root mean square surface roughness of no more than 2 nanometers over an area of at least micrometers by 10 micrometers.
The device structure of claim 1, further comprising a nitride layer on the growth surface and between the substrate and the N-polar group I II -nitride layers, wherein an orientation of the nitride layer is different from an N-polar orientation.
The device structure of claim 1, wherein the substrate is a nitridized misoriented substrate.
The device structure of claim 1, wherein -e lye i" tr a nsition ayer, and an atomic structure of a surface of the transition layer adjacent to the N-polar group I II -nitride layers results in the N-polar group I II -nitride layers, grown on top of the transition layer, having the N-polar [000-1] orientation.
The device structure of claim 1, wherein the N- polar group I II -nitride layers have a threading dislocation density of at most on an order of 109 cm2.
canceled
The device structure of claim 2 1, wherein the transition layer is doped with magnesium.
The device structure of claim 2 1 wherein the miller indices are h =1, i= 0, k = 0 and 1= -1 and the substrate is silicon carbide.
The device structure of claim 2 1, wherein the miller indices are h = 0, i= 0, k = 0 and 1= 1 and the substrate is sapphire.
The device structure of claim 2 1, wherein the miller indices are h =1, k = 1, 1= 1 and the substrate is silicon.
The device structure of claim 2 1, wherein the substrate is (001) Si.
The device structure of claim 2 1, wherein: the N-polar group I II -nitride layers are doped or undoped to form a device structure for an N-face transistor or light emitting device, a surface of the transition layer adjacent to the N-polar group I II -nitride layers results in the N-polar group I II -nitride layers grown on top of the transition layer having the N-polar [000-1] orientation.
The device structure of claim 2 1, wherein a portion of the transition layer adjacent to a first surface of the transition layer is Ga-polar and a portion of the transition layer adjacent to a second surface of the transition layer is N-polar.
The device structure of claim 21, wherein the misorientation angle is between 0.5 and degrees.
canceled
canceled
The device structure of claim [[18]] 1, wherein: at least one of the N-polar group I II -nitride layers includes a channel of the device structure, at least one of the N-polar group I II -nitride layers is a misoriented N-face layer, and the channel is oriented, with respect to a misorientation direction of the misoriented N-face layer.
A method for fabricating an N-polar group I II -nitride device structure, comprising: obtaining a growth surface of a substrate, wherein the growth surface has a misorientation angle relative to a miller indexed crystallographic plane [h, i, k, 1] of the substrate, where h, i, k, 1 are miller indices; formng a--plar Gallium st ridee tGa\) aver Qfl th !m oth s u rface; -4- G&C 30794.311-US-C l forming a t ra n sition layer on the Ga-polar G aN la y er vr ove the grcwh I fa, wherein the transitio n layer sets an N-polar [000-1] orientation for one or more subsequent layers formed on the transition layer; and growing ft" one or more N-polar group I II -nitride l6yef layers on the transition layer, wherein: the N-polar g ro u p III -nit r ide la y ers include a GaN la y er the N-polar group I II -nitride 1ayef-he s la y ers have the N-polar [000-1] orientation set by the tr a nsition layer, and the N-polar group I II -nitride layers have a top surface that is smooth with a root mean square surface roughness of no more than 2 nanometers over an area of at least micrometers by 10 micrometers.
The method of claim 19, foj±comprising doping the spnsitinlayer with magnesium.
A device structure, comprising: a substrate having a growth surface, wherein the growth surface has a misorientation angle relative to a miller indexed crystallographic plane [h, i, k, 1] of the substrate, where h, i, k, 1 are miller indices; and a gr oup I I -N transitio n layer on or above the growth surface, wherein: the g r oup I II -N transition layer sets an N-polar [000-1] orientation for one or more subsequent layers formed on the layer, and a portion of the g rou p III -N transition layer adjacent the growth surface is diff~ciit fi-&m afl N p lar group Iii nirideor Ga-p olar; and one or more N-polar group I II -nitride layers on the group III -N transition layer, wherein the N-polar group I II -nitride layers have the N-polar [000-1] orientation set by the groupIIIN ransitian _ layer.
A device structure, comprising: a substrate comprising sapphire, silicon, or SiC, the substrate having a growth surface, wherein the growth surface has a misorientation angle relative to a miller indexed crystallographic plane of the substrate; a transition layer on the Ga-p olar (G aN layer or ab ove thc gr owth s ur fac e, wherein the transition layer sets an N-polar [000-1] orientation for one or more subsequent layers formed on the transitin _ layer; and one or more N-polar group I II -nitride layers on the transition layer, wherein the one or more N-polar group I II-nitride layers have the N-polar [000-1] orientation set by the transition layer and the one or more N-polar g- rou p III -nitride layers include a G aN layer.
Layer stacks claimed or described, ordered top of device to substrate.
N-polar group III-nitride device structure
N-face HEMT transistor
Materials described outside the worked examples.
misoriented substrate
Ga-polar GaN layer
GaN
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 5(b) shows an atomic force microscope 5 (AFM) image of N- face GaN grown by MOC V D on a nitrided sapphire substrate
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
RMS surface roughness of N-polar group III-nitride top surface, no more than 2 nm over 10x10 µm area | ≤ 2 nm | N-polar group III-nitride layers |
Threading dislocation density of N-polar group III-nitride layers, at most ~10^9 cm^-2 |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
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US 8,455,885Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 illustrates a process cha rt in accordance with the present invention, for the growth on sapphire.
FIG. 2A illustrates a process chart in accordance with the present invention, for the 25 growth on silicon carbide.
FIG. 3 illustrates a process chart in accordance with the present invention, for the growth of semi- insulating GaN on sapphire. 30
FIG. 4A illustrates a process chart in accordance with the present invention, for the growth of semi-insulating GaN on silicon carbide substrate.
FIG. 5(b) shows an atomic force microscope 5 (AFM) image of N- face GaN grown by MOC V D on a nitrided sapphire substrate
FIG. 6 shows transmission electron micrographs, under different imaging conditions, of an N-face GaN film grown using the present invention
FIG. 7(b) shows photoluminescence (PL) from MQWs 10 comprising 5 x (3 nm thick In o.1Ga0. 9N/8 nm thick GaN).
FIG. 8 shows X-ray Diffraction (XRD) of N-face nitride MQWs comprising 5 x (4 nm thick In 0.12Gao.ss N/10 nm thick GaN).
FIG. 9 is a graph showing SIMS results of oxygen impurities as a function of temperature. 15
FIG. 10 is a graph showing SIMS results of carbon impurities as a function of temperature.
FIG. 11(a) and 11(b) are graphs of SIMS results of Mg incorporation in an N-face (
FIGS. 12a-12f illustrate optical micrographs of 0.8 micron thick GaN films grown 20 on sapphire substrates in accordance with the present invention.
FIG. 13 illustrates one or more embodiments of the present invention that incorporate growth of additional I II -nitride films.
FIGS. 14A-14C illustrate micrographs of N-polar films grown on various substrates in accordance with one or more embodiments of the present invention. 25
FIGS. 15 A-B illustrate micrographs of the GaN surface showing surface topologies.
FIGS. 16A-B illustrate micrographs of a GaN film produced in one or more embodiments of the present invention.
FIG. 17 illustrates one or more embodiments of the present invention. 30 7
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A device structure, comprising: a substrate having a growth surface, wherein the growth surface has a misorientation angle relative to a miller indexed crystallographic plane [h, i, k, 1] of the substrate, where h, i, k, 1 are miller indices; ~~ro~h ------- --------------- \GNlyro h o-oth surfa cv a-polar---- (I ---iur Nitride ------ a rL; ===i4Ji l ayer on the G a- pol ar G aN la y er -tr- e 1i-±th-w ±-5:r-ftee, w herein the transitio n layer sets an N-polar [000-1] orientation for one or more subsequent layers formed on the transition layer; and one or more N-polar group I II -nitride layers on the transition layer, wherein: the N-po l ar g roup III-n itride la y ers i nc l ude a G aN la y er, the N-polar group I II -nitride layers have the N-polar [000-1] orientation set by the transition layer, and the N-polar group I II -nitride layers have a top surface that is smooth with a root mean square surface roughness of no more than 2 nanometers over an area of at least micrometers by 10 micrometers.
The device structure of claim 1, further comprising a nitride layer on the growth surface and between the substrate and the N-polar group I II -nitride layers, wherein an orientation of the nitride layer is different from an N-polar orientation.
The device structure of claim 1, wherein the substrate is a nitridized misoriented substrate.
The device structure of claim 1, wherein -e lye i" tr a nsition ayer, and an atomic structure of a surface of the transition layer adjacent to the N-polar group I II -nitride layers results in the N-polar group I II -nitride layers, grown on top of the transition layer, having the N-polar [000-1] orientation.
The device structure of claim 1, wherein the N- polar group I II -nitride layers have a threading dislocation density of at most on an order of 109 cm2.
canceled
The device structure of claim 2 1, wherein the transition layer is doped with magnesium.
The device structure of claim 2 1 wherein the miller indices are h =1, i= 0, k = 0 and 1= -1 and the substrate is silicon carbide.
The device structure of claim 2 1, wherein the miller indices are h = 0, i= 0, k = 0 and 1= 1 and the substrate is sapphire.
The device structure of claim 2 1, wherein the miller indices are h =1, k = 1, 1= 1 and the substrate is silicon.
The device structure of claim 2 1, wherein the substrate is (001) Si.
The device structure of claim 2 1, wherein: the N-polar group I II -nitride layers are doped or undoped to form a device structure for an N-face transistor or light emitting device, a surface of the transition layer adjacent to the N-polar group I II -nitride layers results in the N-polar group I II -nitride layers grown on top of the transition layer having the N-polar [000-1] orientation.
The device structure of claim 2 1, wherein a portion of the transition layer adjacent to a first surface of the transition layer is Ga-polar and a portion of the transition layer adjacent to a second surface of the transition layer is N-polar.
The device structure of claim 21, wherein the misorientation angle is between 0.5 and degrees.
canceled
canceled
The device structure of claim [[18]] 1, wherein: at least one of the N-polar group I II -nitride layers includes a channel of the device structure, at least one of the N-polar group I II -nitride layers is a misoriented N-face layer, and the channel is oriented, with respect to a misorientation direction of the misoriented N-face layer.
A method for fabricating an N-polar group I II -nitride device structure, comprising: obtaining a growth surface of a substrate, wherein the growth surface has a misorientation angle relative to a miller indexed crystallographic plane [h, i, k, 1] of the substrate, where h, i, k, 1 are miller indices; formng a--plar Gallium st ridee tGa\) aver Qfl th !m oth s u rface; -4- G&C 30794.311-US-C l forming a t ra n sition layer on the Ga-polar G aN la y er vr ove the grcwh I fa, wherein the transitio n layer sets an N-polar [000-1] orientation for one or more subsequent layers formed on the transition layer; and growing ft" one or more N-polar group I II -nitride l6yef layers on the transition layer, wherein: the N-polar g ro u p III -nit r ide la y ers include a GaN la y er the N-polar group I II -nitride 1ayef-he s la y ers have the N-polar [000-1] orientation set by the tr a nsition layer, and the N-polar group I II -nitride layers have a top surface that is smooth with a root mean square surface roughness of no more than 2 nanometers over an area of at least micrometers by 10 micrometers.
The method of claim 19, foj±comprising doping the spnsitinlayer with magnesium.
A device structure, comprising: a substrate having a growth surface, wherein the growth surface has a misorientation angle relative to a miller indexed crystallographic plane [h, i, k, 1] of the substrate, where h, i, k, 1 are miller indices; and a gr oup I I -N transitio n layer on or above the growth surface, wherein: the g r oup I II -N transition layer sets an N-polar [000-1] orientation for one or more subsequent layers formed on the layer, and a portion of the g rou p III -N transition layer adjacent the growth surface is diff~ciit fi-&m afl N p lar group Iii nirideor Ga-p olar; and one or more N-polar group I II -nitride layers on the group III -N transition layer, wherein the N-polar group I II -nitride layers have the N-polar [000-1] orientation set by the groupIIIN ransitian _ layer.
A device structure, comprising: a substrate comprising sapphire, silicon, or SiC, the substrate having a growth surface, wherein the growth surface has a misorientation angle relative to a miller indexed crystallographic plane of the substrate; a transition layer on the Ga-p olar (G aN layer or ab ove thc gr owth s ur fac e, wherein the transition layer sets an N-polar [000-1] orientation for one or more subsequent layers formed on the transitin _ layer; and one or more N-polar group I II -nitride layers on the transition layer, wherein the one or more N-polar group I II-nitride layers have the N-polar [000-1] orientation set by the transition layer and the one or more N-polar g- rou p III -nitride layers include a G aN layer.
Layer stacks claimed or described, ordered top of device to substrate.
N-polar group III-nitride device structure
N-face HEMT transistor
Materials described outside the worked examples.
misoriented substrate
Ga-polar GaN layer
GaN
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 5(b) shows an atomic force microscope 5 (AFM) image of N- face GaN grown by MOC V D on a nitrided sapphire substrate
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
RMS surface roughness of N-polar group III-nitride top surface, no more than 2 nm over 10x10 µm area | ≤ 2 nm | N-polar group III-nitride layers |
Threading dislocation density of N-polar group III-nitride layers, at most ~10^9 cm^-2 |
Related documents with shared materials, methods, properties, or citations.
N-face light emitting device (LED/LD)
transition layer
N-polar group III-nitride layers
magnesium dopant
Mg
silicon carbide substrate
SiC
sapphire substrate
Al₂O₃
silicon substrate
Si
nitride layer (non-N-polar)
InN
AlN
InGaN
InxGa₁-xN
(Al,Ga,In)N:Mg
FIG. 6 shows transmission electron micrographs, under different imaging conditions, of an N-face GaN film grown using the present invention
FIG. 7(b) shows photoluminescence (PL) from MQWs 10 comprising 5 x (3 nm thick In o.1Ga0. 9N/8 nm thick GaN).
FIG. 7(b) shows photoluminescence (PL) from MQWs 10 comprising 5 x (3 nm thick In o.1Ga0. 9N/8 nm thick GaN).
FIG. 8 shows X-ray Diffraction (XRD) of N-face nitride MQWs comprising 5 x (4 nm thick In 0.12Gao.ss N/10 nm thick GaN).
FIG. 9 is a graph showing SIMS results of oxygen impurities as a function of temperature. 15
FIG. 9 is a graph showing SIMS results of oxygen impurities as a function of temperature. 15
FIG. 10 is a graph showing SIMS results of carbon impurities as a function of temperature.
FIG. 10 is a graph showing SIMS results of carbon impurities as a function of temperature.
N-polar group III-nitride layers |
Misorientation angle of substrate growth surface relative to miller indexed plane [h,i,k,l], range 0.5 to 10 degrees | 0.5–10 degrees | misoriented substrate |
Thickness | 1–10000 nm | — |
Thickness | 10–1000 nm | — |
Thickness | 0.1–2 nm | — |
Thickness | ≥ 2 nm | — |
Thickness | ≥ 10 µm | — |
N-face light emitting device (LED/LD)
transition layer
N-polar group III-nitride layers
magnesium dopant
Mg
silicon carbide substrate
SiC
sapphire substrate
Al₂O₃
silicon substrate
Si
nitride layer (non-N-polar)
InN
AlN
InGaN
InxGa₁-xN
(Al,Ga,In)N:Mg
FIG. 6 shows transmission electron micrographs, under different imaging conditions, of an N-face GaN film grown using the present invention
FIG. 7(b) shows photoluminescence (PL) from MQWs 10 comprising 5 x (3 nm thick In o.1Ga0. 9N/8 nm thick GaN).
FIG. 7(b) shows photoluminescence (PL) from MQWs 10 comprising 5 x (3 nm thick In o.1Ga0. 9N/8 nm thick GaN).
FIG. 8 shows X-ray Diffraction (XRD) of N-face nitride MQWs comprising 5 x (4 nm thick In 0.12Gao.ss N/10 nm thick GaN).
FIG. 9 is a graph showing SIMS results of oxygen impurities as a function of temperature. 15
FIG. 9 is a graph showing SIMS results of oxygen impurities as a function of temperature. 15
FIG. 10 is a graph showing SIMS results of carbon impurities as a function of temperature.
FIG. 10 is a graph showing SIMS results of carbon impurities as a function of temperature.
N-polar group III-nitride layers |
Misorientation angle of substrate growth surface relative to miller indexed plane [h,i,k,l], range 0.5 to 10 degrees | 0.5–10 degrees | misoriented substrate |
Thickness | 1–10000 nm | — |
Thickness | 10–1000 nm | — |
Thickness | 0.1–2 nm | — |
Thickness | ≥ 2 nm | — |
Thickness | ≥ 10 µm | — |
N-face light emitting device (LED/LD)
transition layer
N-polar group III-nitride layers
magnesium dopant
Mg
silicon carbide substrate
SiC
sapphire substrate
Al₂O₃
silicon substrate
Si
nitride layer (non-N-polar)
InN
AlN
InGaN
InxGa₁-xN
(Al,Ga,In)N:Mg
FIG. 6 shows transmission electron micrographs, under different imaging conditions, of an N-face GaN film grown using the present invention
FIG. 7(b) shows photoluminescence (PL) from MQWs 10 comprising 5 x (3 nm thick In o.1Ga0. 9N/8 nm thick GaN).
FIG. 7(b) shows photoluminescence (PL) from MQWs 10 comprising 5 x (3 nm thick In o.1Ga0. 9N/8 nm thick GaN).
FIG. 8 shows X-ray Diffraction (XRD) of N-face nitride MQWs comprising 5 x (4 nm thick In 0.12Gao.ss N/10 nm thick GaN).
FIG. 9 is a graph showing SIMS results of oxygen impurities as a function of temperature. 15
FIG. 9 is a graph showing SIMS results of oxygen impurities as a function of temperature. 15
FIG. 10 is a graph showing SIMS results of carbon impurities as a function of temperature.
FIG. 10 is a graph showing SIMS results of carbon impurities as a function of temperature.
N-polar group III-nitride layers |
Misorientation angle of substrate growth surface relative to miller indexed plane [h,i,k,l], range 0.5 to 10 degrees | 0.5–10 degrees | misoriented substrate |
Thickness | 1–10000 nm | — |
Thickness | 10–1000 nm | — |
Thickness | 0.1–2 nm | — |
Thickness | ≥ 2 nm | — |
Thickness | ≥ 10 µm | — |
N-face light emitting device (LED/LD)
transition layer
N-polar group III-nitride layers
magnesium dopant
Mg
silicon carbide substrate
SiC
sapphire substrate
Al₂O₃
silicon substrate
Si
nitride layer (non-N-polar)
InN
AlN
InGaN
InxGa₁-xN
(Al,Ga,In)N:Mg
FIG. 6 shows transmission electron micrographs, under different imaging conditions, of an N-face GaN film grown using the present invention
FIG. 7(b) shows photoluminescence (PL) from MQWs 10 comprising 5 x (3 nm thick In o.1Ga0. 9N/8 nm thick GaN).
FIG. 7(b) shows photoluminescence (PL) from MQWs 10 comprising 5 x (3 nm thick In o.1Ga0. 9N/8 nm thick GaN).
FIG. 8 shows X-ray Diffraction (XRD) of N-face nitride MQWs comprising 5 x (4 nm thick In 0.12Gao.ss N/10 nm thick GaN).
FIG. 9 is a graph showing SIMS results of oxygen impurities as a function of temperature. 15
FIG. 9 is a graph showing SIMS results of oxygen impurities as a function of temperature. 15
FIG. 10 is a graph showing SIMS results of carbon impurities as a function of temperature.
FIG. 10 is a graph showing SIMS results of carbon impurities as a function of temperature.
N-polar group III-nitride layers |
Misorientation angle of substrate growth surface relative to miller indexed plane [h,i,k,l], range 0.5 to 10 degrees | 0.5–10 degrees | misoriented substrate |
Thickness | 1–10000 nm | — |
Thickness | 10–1000 nm | — |
Thickness | 0.1–2 nm | — |
Thickness | ≥ 2 nm | — |
Thickness | ≥ 10 µm | — |
