Patent
US 8,338,313METHOD FOR NONDESTRUCTIVE LIFT-OFF OF GaN FROM SAPPHIRE SUBSTRATE UTILIZING A SOLID-STATE LASER
Guoyi Zhang
US
Copyright © 2026 Matter42. All rights reserved.
Patent
Atlas literature
Patent
US 8,338,313Patent drawings and their descriptions. Click a drawing to enlarge it.
Figure 1 is a photograph of the damages at the edges of GaN after the lift-off by a large laser spot in conventional techniques.
Figure 2A shows the energy distribution in a laser spot in conventional lift-off techniques.
Figure 2B shows the energy distribution in a small laser spot in the presently disclosed techniques.
Figure 3 is a photograph of the surface of a device after laser lift-off using a small laser spot in according to the present invention.
Figure 4 is a microscopic photograph at 500 magnification of a device surface after laser lift-off in a first example in according to the present invention.
Figure 5 is a microscopic photograph at 500 magnification of a device surface after laser lift-off in a first example in according to the present invention.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method for non-destructively lifting a I II-V semiconductor device from a sapphire substrate, comprising: obtaining a I II-V semiconductor layer grown on a sapphire substrate at an interface; irradiating a laser beam through the sapphire substrate, wherein the laser beam forms a laser spot at the interface between the I II-V semiconductor layer and the sapphire substrate, wherein the laser spot has a distance between two farthest corners or a longest diameter smaller than 400 [m; and scanning the laser beam across the interface between the I II-V semiconductor layer and the sapphire substrate to form a plurality of laser spots at the interface to non-destructively separate the I II-V semiconductor layer from the sapphire substrate, wherein the distance between the centers of ad j acent laser spots at the interface is in a range of about 30 m and about 100 m.
The method of claim 1, wherein the perimeter of the laser spot has a distance between two farthest corners or a longest diameter no more than 150 micrometers.
The method of claim 1, wherein the perimeter of the laser spot has a length between about 3 m and 1000 m.
The method of claim 1, wherein the perimeter of the laser spot has a length between about 100 m and 400 [m.
The method of claim 1, wherein the laser spot at the interface has a width of about 30 microns m.
The method of claim 1, wherein the laser spot at the interface has a width of about 100 microns m.
The method of claim 1, wherein the distance between the centers of adjacent laser spots is about the same as the width of the laser spot.
The method of claim 1, wherein the laser spot at the interface has a shape selected from the group consisting of a square, a rectangle, a polygon, a circle, and an elliptical.
The method of claim 1, wherein the laser spot has a substantially Gaussian energy distribution at the interface between the I II -V semiconductor layer and the sapphire substrate.
The method of claim 1, wherein the laser beam is emitted by a solid- state laser device.
The method of claim 1, further comprising: bonding a conductive layer on a surface of the I II -V semiconductor layer opposing the interface between the I II -V semiconductor layer and the sapphire substrate.
The method of claim 1, wherein the I II -V semiconductor material Page 5 comprises GaN.
The method of claim 1, wherein the I II-V semiconductor material comprises a nitride material.
6-20:
23 canceled
A method for non-destructively lifting a I II-V semiconductor device from a sapphire substrate, comprising: obtaining a I II-V semiconductor layer grown on a sapphire substrate at an interface; irradiating a laser beam through the sapphire substrate, wherein the laser beam forms a laser spot at the interface between the I II-V semiconductor layer and the sapphire substrate, wherein the perimeter of the laser spot has a length between about 3 g m and 1000 [m; and scanning the laser beam across the interface between the I II-V form a plurality of laser spots at the interface to semiconductor layer from the sapphire substrate, adjacent laser spots at the interface is in a range
The method of claim 32, wherein the perimeter 100 g m and 400 [m.
The method of claim 32, wherein the laser spot a longest diameter smaller than 400 [m.
The method of claim 32, wherein the laser semiconductor layer and the sapphire substrate to non-destructively separate the I II-V wherein the distance between the centers of about 30 g m and about 100 im. of the laser spot has a length between about has a distance between two farthest corners or beam is emitted by a solid- state laser device.
Embodiments described in the patent, grouped by the materials and process steps they use.
5 materials2 process steps
A vertical structure GaN-based device is lifted off a sapphire substrate. A GaN epitaxial wafer on sapphire is diced into device cells. A Cu layer is bonded to the GaN surface using a Pd/In bonding stack: Pd sputtered to 200 nm, In thermally evaporated to 600 nm, bonded at 200°C and 1 MPa for 20 minutes. Laser lift-off is performed using an improved solid-state harmonic frequency laser (e.g., YAG) with energy density 600 mJ/cm², frequency 20 Hz, square spot ~30 µm side, center-to-center spacing 30 µm, scanning point-by-point and line-by-line. The lift-off surface is uniform and free of damage at 500x magnification.
2 materials1 process step
A vertical structure GaN-based device is lifted off a sapphire substrate following similar steps to Example 1 (text truncated in source).
Materials described outside the worked examples.
III-V semiconductor layer
conductive layer
III-V nitride material
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
Thickness | 3–1000 µm | — |
Thickness |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 8,338,313Patent drawings and their descriptions. Click a drawing to enlarge it.
Figure 1 is a photograph of the damages at the edges of GaN after the lift-off by a large laser spot in conventional techniques.
Figure 2A shows the energy distribution in a laser spot in conventional lift-off techniques.
Figure 2B shows the energy distribution in a small laser spot in the presently disclosed techniques.
Figure 3 is a photograph of the surface of a device after laser lift-off using a small laser spot in according to the present invention.
Figure 4 is a microscopic photograph at 500 magnification of a device surface after laser lift-off in a first example in according to the present invention.
Figure 5 is a microscopic photograph at 500 magnification of a device surface after laser lift-off in a first example in according to the present invention.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method for non-destructively lifting a I II-V semiconductor device from a sapphire substrate, comprising: obtaining a I II-V semiconductor layer grown on a sapphire substrate at an interface; irradiating a laser beam through the sapphire substrate, wherein the laser beam forms a laser spot at the interface between the I II-V semiconductor layer and the sapphire substrate, wherein the laser spot has a distance between two farthest corners or a longest diameter smaller than 400 [m; and scanning the laser beam across the interface between the I II-V semiconductor layer and the sapphire substrate to form a plurality of laser spots at the interface to non-destructively separate the I II-V semiconductor layer from the sapphire substrate, wherein the distance between the centers of ad j acent laser spots at the interface is in a range of about 30 m and about 100 m.
The method of claim 1, wherein the perimeter of the laser spot has a distance between two farthest corners or a longest diameter no more than 150 micrometers.
The method of claim 1, wherein the perimeter of the laser spot has a length between about 3 m and 1000 m.
The method of claim 1, wherein the perimeter of the laser spot has a length between about 100 m and 400 [m.
The method of claim 1, wherein the laser spot at the interface has a width of about 30 microns m.
The method of claim 1, wherein the laser spot at the interface has a width of about 100 microns m.
The method of claim 1, wherein the distance between the centers of adjacent laser spots is about the same as the width of the laser spot.
The method of claim 1, wherein the laser spot at the interface has a shape selected from the group consisting of a square, a rectangle, a polygon, a circle, and an elliptical.
The method of claim 1, wherein the laser spot has a substantially Gaussian energy distribution at the interface between the I II -V semiconductor layer and the sapphire substrate.
The method of claim 1, wherein the laser beam is emitted by a solid- state laser device.
The method of claim 1, further comprising: bonding a conductive layer on a surface of the I II -V semiconductor layer opposing the interface between the I II -V semiconductor layer and the sapphire substrate.
The method of claim 1, wherein the I II -V semiconductor material Page 5 comprises GaN.
The method of claim 1, wherein the I II-V semiconductor material comprises a nitride material.
6-20:
23 canceled
A method for non-destructively lifting a I II-V semiconductor device from a sapphire substrate, comprising: obtaining a I II-V semiconductor layer grown on a sapphire substrate at an interface; irradiating a laser beam through the sapphire substrate, wherein the laser beam forms a laser spot at the interface between the I II-V semiconductor layer and the sapphire substrate, wherein the perimeter of the laser spot has a length between about 3 g m and 1000 [m; and scanning the laser beam across the interface between the I II-V form a plurality of laser spots at the interface to semiconductor layer from the sapphire substrate, adjacent laser spots at the interface is in a range
The method of claim 32, wherein the perimeter 100 g m and 400 [m.
The method of claim 32, wherein the laser spot a longest diameter smaller than 400 [m.
The method of claim 32, wherein the laser semiconductor layer and the sapphire substrate to non-destructively separate the I II-V wherein the distance between the centers of about 30 g m and about 100 im. of the laser spot has a length between about has a distance between two farthest corners or beam is emitted by a solid- state laser device.
Embodiments described in the patent, grouped by the materials and process steps they use.
5 materials2 process steps
A vertical structure GaN-based device is lifted off a sapphire substrate. A GaN epitaxial wafer on sapphire is diced into device cells. A Cu layer is bonded to the GaN surface using a Pd/In bonding stack: Pd sputtered to 200 nm, In thermally evaporated to 600 nm, bonded at 200°C and 1 MPa for 20 minutes. Laser lift-off is performed using an improved solid-state harmonic frequency laser (e.g., YAG) with energy density 600 mJ/cm², frequency 20 Hz, square spot ~30 µm side, center-to-center spacing 30 µm, scanning point-by-point and line-by-line. The lift-off surface is uniform and free of damage at 500x magnification.
2 materials1 process step
A vertical structure GaN-based device is lifted off a sapphire substrate following similar steps to Example 1 (text truncated in source).
Materials described outside the worked examples.
III-V semiconductor layer
conductive layer
III-V nitride material
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
Thickness | 3–1000 µm | — |
Thickness |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 8,338,313Patent drawings and their descriptions. Click a drawing to enlarge it.
Figure 1 is a photograph of the damages at the edges of GaN after the lift-off by a large laser spot in conventional techniques.
Figure 2A shows the energy distribution in a laser spot in conventional lift-off techniques.
Figure 2B shows the energy distribution in a small laser spot in the presently disclosed techniques.
Figure 3 is a photograph of the surface of a device after laser lift-off using a small laser spot in according to the present invention.
Figure 4 is a microscopic photograph at 500 magnification of a device surface after laser lift-off in a first example in according to the present invention.
Figure 5 is a microscopic photograph at 500 magnification of a device surface after laser lift-off in a first example in according to the present invention.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method for non-destructively lifting a I II-V semiconductor device from a sapphire substrate, comprising: obtaining a I II-V semiconductor layer grown on a sapphire substrate at an interface; irradiating a laser beam through the sapphire substrate, wherein the laser beam forms a laser spot at the interface between the I II-V semiconductor layer and the sapphire substrate, wherein the laser spot has a distance between two farthest corners or a longest diameter smaller than 400 [m; and scanning the laser beam across the interface between the I II-V semiconductor layer and the sapphire substrate to form a plurality of laser spots at the interface to non-destructively separate the I II-V semiconductor layer from the sapphire substrate, wherein the distance between the centers of ad j acent laser spots at the interface is in a range of about 30 m and about 100 m.
The method of claim 1, wherein the perimeter of the laser spot has a distance between two farthest corners or a longest diameter no more than 150 micrometers.
The method of claim 1, wherein the perimeter of the laser spot has a length between about 3 m and 1000 m.
The method of claim 1, wherein the perimeter of the laser spot has a length between about 100 m and 400 [m.
The method of claim 1, wherein the laser spot at the interface has a width of about 30 microns m.
The method of claim 1, wherein the laser spot at the interface has a width of about 100 microns m.
The method of claim 1, wherein the distance between the centers of adjacent laser spots is about the same as the width of the laser spot.
The method of claim 1, wherein the laser spot at the interface has a shape selected from the group consisting of a square, a rectangle, a polygon, a circle, and an elliptical.
The method of claim 1, wherein the laser spot has a substantially Gaussian energy distribution at the interface between the I II -V semiconductor layer and the sapphire substrate.
The method of claim 1, wherein the laser beam is emitted by a solid- state laser device.
The method of claim 1, further comprising: bonding a conductive layer on a surface of the I II -V semiconductor layer opposing the interface between the I II -V semiconductor layer and the sapphire substrate.
The method of claim 1, wherein the I II -V semiconductor material Page 5 comprises GaN.
The method of claim 1, wherein the I II-V semiconductor material comprises a nitride material.
6-20:
23 canceled
A method for non-destructively lifting a I II-V semiconductor device from a sapphire substrate, comprising: obtaining a I II-V semiconductor layer grown on a sapphire substrate at an interface; irradiating a laser beam through the sapphire substrate, wherein the laser beam forms a laser spot at the interface between the I II-V semiconductor layer and the sapphire substrate, wherein the perimeter of the laser spot has a length between about 3 g m and 1000 [m; and scanning the laser beam across the interface between the I II-V form a plurality of laser spots at the interface to semiconductor layer from the sapphire substrate, adjacent laser spots at the interface is in a range
The method of claim 32, wherein the perimeter 100 g m and 400 [m.
The method of claim 32, wherein the laser spot a longest diameter smaller than 400 [m.
The method of claim 32, wherein the laser semiconductor layer and the sapphire substrate to non-destructively separate the I II-V wherein the distance between the centers of about 30 g m and about 100 im. of the laser spot has a length between about has a distance between two farthest corners or beam is emitted by a solid- state laser device.
Embodiments described in the patent, grouped by the materials and process steps they use.
5 materials2 process steps
A vertical structure GaN-based device is lifted off a sapphire substrate. A GaN epitaxial wafer on sapphire is diced into device cells. A Cu layer is bonded to the GaN surface using a Pd/In bonding stack: Pd sputtered to 200 nm, In thermally evaporated to 600 nm, bonded at 200°C and 1 MPa for 20 minutes. Laser lift-off is performed using an improved solid-state harmonic frequency laser (e.g., YAG) with energy density 600 mJ/cm², frequency 20 Hz, square spot ~30 µm side, center-to-center spacing 30 µm, scanning point-by-point and line-by-line. The lift-off surface is uniform and free of damage at 500x magnification.
2 materials1 process step
A vertical structure GaN-based device is lifted off a sapphire substrate following similar steps to Example 1 (text truncated in source).
Materials described outside the worked examples.
III-V semiconductor layer
conductive layer
III-V nitride material
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
Thickness | 3–1000 µm | — |
Thickness |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 8,338,313Patent drawings and their descriptions. Click a drawing to enlarge it.
Figure 1 is a photograph of the damages at the edges of GaN after the lift-off by a large laser spot in conventional techniques.
Figure 2A shows the energy distribution in a laser spot in conventional lift-off techniques.
Figure 2B shows the energy distribution in a small laser spot in the presently disclosed techniques.
Figure 3 is a photograph of the surface of a device after laser lift-off using a small laser spot in according to the present invention.
Figure 4 is a microscopic photograph at 500 magnification of a device surface after laser lift-off in a first example in according to the present invention.
Figure 5 is a microscopic photograph at 500 magnification of a device surface after laser lift-off in a first example in according to the present invention.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method for non-destructively lifting a I II-V semiconductor device from a sapphire substrate, comprising: obtaining a I II-V semiconductor layer grown on a sapphire substrate at an interface; irradiating a laser beam through the sapphire substrate, wherein the laser beam forms a laser spot at the interface between the I II-V semiconductor layer and the sapphire substrate, wherein the laser spot has a distance between two farthest corners or a longest diameter smaller than 400 [m; and scanning the laser beam across the interface between the I II-V semiconductor layer and the sapphire substrate to form a plurality of laser spots at the interface to non-destructively separate the I II-V semiconductor layer from the sapphire substrate, wherein the distance between the centers of ad j acent laser spots at the interface is in a range of about 30 m and about 100 m.
The method of claim 1, wherein the perimeter of the laser spot has a distance between two farthest corners or a longest diameter no more than 150 micrometers.
The method of claim 1, wherein the perimeter of the laser spot has a length between about 3 m and 1000 m.
The method of claim 1, wherein the perimeter of the laser spot has a length between about 100 m and 400 [m.
The method of claim 1, wherein the laser spot at the interface has a width of about 30 microns m.
The method of claim 1, wherein the laser spot at the interface has a width of about 100 microns m.
The method of claim 1, wherein the distance between the centers of adjacent laser spots is about the same as the width of the laser spot.
The method of claim 1, wherein the laser spot at the interface has a shape selected from the group consisting of a square, a rectangle, a polygon, a circle, and an elliptical.
The method of claim 1, wherein the laser spot has a substantially Gaussian energy distribution at the interface between the I II -V semiconductor layer and the sapphire substrate.
The method of claim 1, wherein the laser beam is emitted by a solid- state laser device.
The method of claim 1, further comprising: bonding a conductive layer on a surface of the I II -V semiconductor layer opposing the interface between the I II -V semiconductor layer and the sapphire substrate.
The method of claim 1, wherein the I II -V semiconductor material Page 5 comprises GaN.
The method of claim 1, wherein the I II-V semiconductor material comprises a nitride material.
6-20:
23 canceled
A method for non-destructively lifting a I II-V semiconductor device from a sapphire substrate, comprising: obtaining a I II-V semiconductor layer grown on a sapphire substrate at an interface; irradiating a laser beam through the sapphire substrate, wherein the laser beam forms a laser spot at the interface between the I II-V semiconductor layer and the sapphire substrate, wherein the perimeter of the laser spot has a length between about 3 g m and 1000 [m; and scanning the laser beam across the interface between the I II-V form a plurality of laser spots at the interface to semiconductor layer from the sapphire substrate, adjacent laser spots at the interface is in a range
The method of claim 32, wherein the perimeter 100 g m and 400 [m.
The method of claim 32, wherein the laser spot a longest diameter smaller than 400 [m.
The method of claim 32, wherein the laser semiconductor layer and the sapphire substrate to non-destructively separate the I II-V wherein the distance between the centers of about 30 g m and about 100 im. of the laser spot has a length between about has a distance between two farthest corners or beam is emitted by a solid- state laser device.
Embodiments described in the patent, grouped by the materials and process steps they use.
5 materials2 process steps
A vertical structure GaN-based device is lifted off a sapphire substrate. A GaN epitaxial wafer on sapphire is diced into device cells. A Cu layer is bonded to the GaN surface using a Pd/In bonding stack: Pd sputtered to 200 nm, In thermally evaporated to 600 nm, bonded at 200°C and 1 MPa for 20 minutes. Laser lift-off is performed using an improved solid-state harmonic frequency laser (e.g., YAG) with energy density 600 mJ/cm², frequency 20 Hz, square spot ~30 µm side, center-to-center spacing 30 µm, scanning point-by-point and line-by-line. The lift-off surface is uniform and free of damage at 500x magnification.
2 materials1 process step
A vertical structure GaN-based device is lifted off a sapphire substrate following similar steps to Example 1 (text truncated in source).
Materials described outside the worked examples.
III-V semiconductor layer
conductive layer
III-V nitride material
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
Thickness | 3–1000 µm | — |
Thickness |
Related documents with shared materials, methods, properties, or citations.
InGaN
AlGaN
| — |
Thickness | 1–250 µm | — |
Thickness | 1–400 µm | — |
Thickness | ≤ 400 µm | — |
Thickness | ≤ 150 µm | — |
Thickness | ≥ 400 µm | — |
Thickness | ≥ 150 µm | — |
InGaN
AlGaN
| — |
Thickness | 1–250 µm | — |
Thickness | 1–400 µm | — |
Thickness | ≤ 400 µm | — |
Thickness | ≤ 150 µm | — |
Thickness | ≥ 400 µm | — |
Thickness | ≥ 150 µm | — |
InGaN
AlGaN
| — |
Thickness | 1–250 µm | — |
Thickness | 1–400 µm | — |
Thickness | ≤ 400 µm | — |
Thickness | ≤ 150 µm | — |
Thickness | ≥ 400 µm | — |
Thickness | ≥ 150 µm | — |
InGaN
AlGaN
| — |
Thickness | 1–250 µm | — |
Thickness | 1–400 µm | — |
Thickness | ≤ 400 µm | — |
Thickness | ≤ 150 µm | — |
Thickness | ≥ 400 µm | — |
Thickness | ≥ 150 µm | — |