Patent
US 10,720,390An Ohmic Metal Structure for GaN Device
Chang-Hwang HUA
US
Copyright © 2026 Matter42. All rights reserved.
Patent
Atlas literature
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US 10,720,390Patent drawings and their descriptions. Click a drawing to enlarge it.
Figure 1 is the cross-sectional schematic showing an embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 2 is the cross-sectional schematic showing another embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 3 is the cross-sectional schematic showing one embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 4A is the top view of the SEM image of an embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 4B is the partial enlarged view of the SEM image of the embodiment of
Figure 4C is the partial enlarged view of the SEM image of the embodiment of
Figure 4D is the cross-sectional view of the TEM image of another embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 4E is the partial enlarged view of the SEM image of the white block region of the embodiment of
Figure 5 is the cross-sectional schematic showing an embodiment of the ohmic metal for GaN device of conventional technology.
Figure 6A is the top view of the SEM image of an embodiment of the ohmic metal (Ti/A l/Ti/Au) for GaN device of conventional technology.
Figure 6B is the partial enlarged view of the SEM image of the embodiment of
Figure 6C is the partial enlarged view of the SEM image of the embodiment of
Figure 6D is the cross-sectional view of the FIB image of an embodiment of the ohmic metal (Ti/Al/Ti/Au) for GaN device of conventional technology.
Figure 6E is the cross-sectional view of the FIB image of another embodiment of the ohmic metal (Ti/A l/Ti/Au) for GaN device of conventional technology.
Figure 6F is the cross-sectional view of the FIB image of one embodiment of the ohmic metal (Ti/Al/Ti/Au) for GaN device of conventional technology.
Figure 7A is the top view of the SEM image of an embodiment of the ohmic metal (Ti/A l/Mo/Au) for GaN device of conventional technology.
Figure 7B is the cross-sectional view of the TEM image along the broken line of the arrow of the embodiment of
Figure 7C is the partial enlarged view of the TEM image of the block R region of the embodiment of
Figure 7D is the partial enlarged view of the TEM image of the block R 1 region of the embodiment of
Figure 7E is the partial enlarged view of the TEM image of the block R₂ region of the embodiment of
Figure 7F is the partial enlarged view of the TEM image of the block R₃ region of the embodiment of
Figure 7G is the partial enlarged view of the TEM image of the block R₄ region of the embodiment of
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
An ohmic metal structure for GaN device comprises: a diffusion barrier seed layer formed on a p semiconductor structure layer, wherein said diffusion barrier seed layer is in contact with said p semiconductor structure layer, wherein said diffusion barrier seed layer is made of Pt, wherein said p semiconductor structure layer is made of one material selected from the group consisting of: GaN and AlGaN; and a plurality of metal layers formed on said diffusion barrier seed layer, wherein said plurality of metal layers comprises: a first metal layer formed on said diffusion barrier seed layer, wherein said first metal layer is made of Ti; a second metal layer formed on said first metal layer, wherein said second metal layer is made of Al;, y y, pp p y y p y; wherein said GaN device is a GaN high electron mobility transistor; wherein said ohmic metal structure forms an n-type ohmic contact with said p semiconductor structure layer. Currently amended
The ohmic metal structure for GaN device according to claim 1, wherein said plurality of metal layers further p s comprise a third metal layer, wherein said third metal layer is formed on said second metal layer, wherein said third metal layer is made of one material selected from the group consisting of: Ni, Mo, Pd, Pt and Ti. Currently amended
The ohmic metal structure for GaN device according to claim 1, wherein said second metal layer has a thickness greater than or equal to 500A and less than or equal to 15ooA. Original
The ohmic metal structure for GaN device according to claim 1, wherein said first metal layer has a thickness greater than or equal to 5 0 A and less than or equal to 250 A. Original
The ohmic metal structure for GaN device according to claim 1, wherein said diffusion barrier seed layer has a thickness greater than or equal to 50 k and less than or equal to 250A. Original
9-11. Canceled
Layer stacks claimed or described, ordered top of device to substrate.
GaN high electron mobility transistor ohmic metal structure
Materials described outside the worked examples.
Platinum diffusion barrier seed layer
Pt
Titanium first metal layer
Ti
Aluminum second metal layer
Al
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
Figure 4A is the top view of the SEM image of an embodiment of the ohmic metal structure for GaN device of the present invention.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
Breakdown voltage of conventional GaN FET with Ti/Al/Ni/Au ohmic metal | 120 V | — |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 10,720,390Patent drawings and their descriptions. Click a drawing to enlarge it.
Figure 1 is the cross-sectional schematic showing an embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 2 is the cross-sectional schematic showing another embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 3 is the cross-sectional schematic showing one embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 4A is the top view of the SEM image of an embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 4B is the partial enlarged view of the SEM image of the embodiment of
Figure 4C is the partial enlarged view of the SEM image of the embodiment of
Figure 4D is the cross-sectional view of the TEM image of another embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 4E is the partial enlarged view of the SEM image of the white block region of the embodiment of
Figure 5 is the cross-sectional schematic showing an embodiment of the ohmic metal for GaN device of conventional technology.
Figure 6A is the top view of the SEM image of an embodiment of the ohmic metal (Ti/A l/Ti/Au) for GaN device of conventional technology.
Figure 6B is the partial enlarged view of the SEM image of the embodiment of
Figure 6C is the partial enlarged view of the SEM image of the embodiment of
Figure 6D is the cross-sectional view of the FIB image of an embodiment of the ohmic metal (Ti/Al/Ti/Au) for GaN device of conventional technology.
Figure 6E is the cross-sectional view of the FIB image of another embodiment of the ohmic metal (Ti/A l/Ti/Au) for GaN device of conventional technology.
Figure 6F is the cross-sectional view of the FIB image of one embodiment of the ohmic metal (Ti/Al/Ti/Au) for GaN device of conventional technology.
Figure 7A is the top view of the SEM image of an embodiment of the ohmic metal (Ti/A l/Mo/Au) for GaN device of conventional technology.
Figure 7B is the cross-sectional view of the TEM image along the broken line of the arrow of the embodiment of
Figure 7C is the partial enlarged view of the TEM image of the block R region of the embodiment of
Figure 7D is the partial enlarged view of the TEM image of the block R 1 region of the embodiment of
Figure 7E is the partial enlarged view of the TEM image of the block R₂ region of the embodiment of
Figure 7F is the partial enlarged view of the TEM image of the block R₃ region of the embodiment of
Figure 7G is the partial enlarged view of the TEM image of the block R₄ region of the embodiment of
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
An ohmic metal structure for GaN device comprises: a diffusion barrier seed layer formed on a p semiconductor structure layer, wherein said diffusion barrier seed layer is in contact with said p semiconductor structure layer, wherein said diffusion barrier seed layer is made of Pt, wherein said p semiconductor structure layer is made of one material selected from the group consisting of: GaN and AlGaN; and a plurality of metal layers formed on said diffusion barrier seed layer, wherein said plurality of metal layers comprises: a first metal layer formed on said diffusion barrier seed layer, wherein said first metal layer is made of Ti; a second metal layer formed on said first metal layer, wherein said second metal layer is made of Al;, y y, pp p y y p y; wherein said GaN device is a GaN high electron mobility transistor; wherein said ohmic metal structure forms an n-type ohmic contact with said p semiconductor structure layer. Currently amended
The ohmic metal structure for GaN device according to claim 1, wherein said plurality of metal layers further p s comprise a third metal layer, wherein said third metal layer is formed on said second metal layer, wherein said third metal layer is made of one material selected from the group consisting of: Ni, Mo, Pd, Pt and Ti. Currently amended
The ohmic metal structure for GaN device according to claim 1, wherein said second metal layer has a thickness greater than or equal to 500A and less than or equal to 15ooA. Original
The ohmic metal structure for GaN device according to claim 1, wherein said first metal layer has a thickness greater than or equal to 5 0 A and less than or equal to 250 A. Original
The ohmic metal structure for GaN device according to claim 1, wherein said diffusion barrier seed layer has a thickness greater than or equal to 50 k and less than or equal to 250A. Original
9-11. Canceled
Layer stacks claimed or described, ordered top of device to substrate.
GaN high electron mobility transistor ohmic metal structure
Materials described outside the worked examples.
Platinum diffusion barrier seed layer
Pt
Titanium first metal layer
Ti
Aluminum second metal layer
Al
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
Figure 4A is the top view of the SEM image of an embodiment of the ohmic metal structure for GaN device of the present invention.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
Breakdown voltage of conventional GaN FET with Ti/Al/Ni/Au ohmic metal | 120 V | — |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 10,720,390Patent drawings and their descriptions. Click a drawing to enlarge it.
Figure 1 is the cross-sectional schematic showing an embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 2 is the cross-sectional schematic showing another embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 3 is the cross-sectional schematic showing one embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 4A is the top view of the SEM image of an embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 4B is the partial enlarged view of the SEM image of the embodiment of
Figure 4C is the partial enlarged view of the SEM image of the embodiment of
Figure 4D is the cross-sectional view of the TEM image of another embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 4E is the partial enlarged view of the SEM image of the white block region of the embodiment of
Figure 5 is the cross-sectional schematic showing an embodiment of the ohmic metal for GaN device of conventional technology.
Figure 6A is the top view of the SEM image of an embodiment of the ohmic metal (Ti/A l/Ti/Au) for GaN device of conventional technology.
Figure 6B is the partial enlarged view of the SEM image of the embodiment of
Figure 6C is the partial enlarged view of the SEM image of the embodiment of
Figure 6D is the cross-sectional view of the FIB image of an embodiment of the ohmic metal (Ti/Al/Ti/Au) for GaN device of conventional technology.
Figure 6E is the cross-sectional view of the FIB image of another embodiment of the ohmic metal (Ti/A l/Ti/Au) for GaN device of conventional technology.
Figure 6F is the cross-sectional view of the FIB image of one embodiment of the ohmic metal (Ti/Al/Ti/Au) for GaN device of conventional technology.
Figure 7A is the top view of the SEM image of an embodiment of the ohmic metal (Ti/A l/Mo/Au) for GaN device of conventional technology.
Figure 7B is the cross-sectional view of the TEM image along the broken line of the arrow of the embodiment of
Figure 7C is the partial enlarged view of the TEM image of the block R region of the embodiment of
Figure 7D is the partial enlarged view of the TEM image of the block R 1 region of the embodiment of
Figure 7E is the partial enlarged view of the TEM image of the block R₂ region of the embodiment of
Figure 7F is the partial enlarged view of the TEM image of the block R₃ region of the embodiment of
Figure 7G is the partial enlarged view of the TEM image of the block R₄ region of the embodiment of
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
An ohmic metal structure for GaN device comprises: a diffusion barrier seed layer formed on a p semiconductor structure layer, wherein said diffusion barrier seed layer is in contact with said p semiconductor structure layer, wherein said diffusion barrier seed layer is made of Pt, wherein said p semiconductor structure layer is made of one material selected from the group consisting of: GaN and AlGaN; and a plurality of metal layers formed on said diffusion barrier seed layer, wherein said plurality of metal layers comprises: a first metal layer formed on said diffusion barrier seed layer, wherein said first metal layer is made of Ti; a second metal layer formed on said first metal layer, wherein said second metal layer is made of Al;, y y, pp p y y p y; wherein said GaN device is a GaN high electron mobility transistor; wherein said ohmic metal structure forms an n-type ohmic contact with said p semiconductor structure layer. Currently amended
The ohmic metal structure for GaN device according to claim 1, wherein said plurality of metal layers further p s comprise a third metal layer, wherein said third metal layer is formed on said second metal layer, wherein said third metal layer is made of one material selected from the group consisting of: Ni, Mo, Pd, Pt and Ti. Currently amended
The ohmic metal structure for GaN device according to claim 1, wherein said second metal layer has a thickness greater than or equal to 500A and less than or equal to 15ooA. Original
The ohmic metal structure for GaN device according to claim 1, wherein said first metal layer has a thickness greater than or equal to 5 0 A and less than or equal to 250 A. Original
The ohmic metal structure for GaN device according to claim 1, wherein said diffusion barrier seed layer has a thickness greater than or equal to 50 k and less than or equal to 250A. Original
9-11. Canceled
Layer stacks claimed or described, ordered top of device to substrate.
GaN high electron mobility transistor ohmic metal structure
Materials described outside the worked examples.
Platinum diffusion barrier seed layer
Pt
Titanium first metal layer
Ti
Aluminum second metal layer
Al
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
Figure 4A is the top view of the SEM image of an embodiment of the ohmic metal structure for GaN device of the present invention.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
Breakdown voltage of conventional GaN FET with Ti/Al/Ni/Au ohmic metal | 120 V | — |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 10,720,390Patent drawings and their descriptions. Click a drawing to enlarge it.
Figure 1 is the cross-sectional schematic showing an embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 2 is the cross-sectional schematic showing another embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 3 is the cross-sectional schematic showing one embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 4A is the top view of the SEM image of an embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 4B is the partial enlarged view of the SEM image of the embodiment of
Figure 4C is the partial enlarged view of the SEM image of the embodiment of
Figure 4D is the cross-sectional view of the TEM image of another embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 4E is the partial enlarged view of the SEM image of the white block region of the embodiment of
Figure 5 is the cross-sectional schematic showing an embodiment of the ohmic metal for GaN device of conventional technology.
Figure 6A is the top view of the SEM image of an embodiment of the ohmic metal (Ti/A l/Ti/Au) for GaN device of conventional technology.
Figure 6B is the partial enlarged view of the SEM image of the embodiment of
Figure 6C is the partial enlarged view of the SEM image of the embodiment of
Figure 6D is the cross-sectional view of the FIB image of an embodiment of the ohmic metal (Ti/Al/Ti/Au) for GaN device of conventional technology.
Figure 6E is the cross-sectional view of the FIB image of another embodiment of the ohmic metal (Ti/A l/Ti/Au) for GaN device of conventional technology.
Figure 6F is the cross-sectional view of the FIB image of one embodiment of the ohmic metal (Ti/Al/Ti/Au) for GaN device of conventional technology.
Figure 7A is the top view of the SEM image of an embodiment of the ohmic metal (Ti/A l/Mo/Au) for GaN device of conventional technology.
Figure 7B is the cross-sectional view of the TEM image along the broken line of the arrow of the embodiment of
Figure 7C is the partial enlarged view of the TEM image of the block R region of the embodiment of
Figure 7D is the partial enlarged view of the TEM image of the block R 1 region of the embodiment of
Figure 7E is the partial enlarged view of the TEM image of the block R₂ region of the embodiment of
Figure 7F is the partial enlarged view of the TEM image of the block R₃ region of the embodiment of
Figure 7G is the partial enlarged view of the TEM image of the block R₄ region of the embodiment of
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
An ohmic metal structure for GaN device comprises: a diffusion barrier seed layer formed on a p semiconductor structure layer, wherein said diffusion barrier seed layer is in contact with said p semiconductor structure layer, wherein said diffusion barrier seed layer is made of Pt, wherein said p semiconductor structure layer is made of one material selected from the group consisting of: GaN and AlGaN; and a plurality of metal layers formed on said diffusion barrier seed layer, wherein said plurality of metal layers comprises: a first metal layer formed on said diffusion barrier seed layer, wherein said first metal layer is made of Ti; a second metal layer formed on said first metal layer, wherein said second metal layer is made of Al;, y y, pp p y y p y; wherein said GaN device is a GaN high electron mobility transistor; wherein said ohmic metal structure forms an n-type ohmic contact with said p semiconductor structure layer. Currently amended
The ohmic metal structure for GaN device according to claim 1, wherein said plurality of metal layers further p s comprise a third metal layer, wherein said third metal layer is formed on said second metal layer, wherein said third metal layer is made of one material selected from the group consisting of: Ni, Mo, Pd, Pt and Ti. Currently amended
The ohmic metal structure for GaN device according to claim 1, wherein said second metal layer has a thickness greater than or equal to 500A and less than or equal to 15ooA. Original
The ohmic metal structure for GaN device according to claim 1, wherein said first metal layer has a thickness greater than or equal to 5 0 A and less than or equal to 250 A. Original
The ohmic metal structure for GaN device according to claim 1, wherein said diffusion barrier seed layer has a thickness greater than or equal to 50 k and less than or equal to 250A. Original
9-11. Canceled
Layer stacks claimed or described, ordered top of device to substrate.
GaN high electron mobility transistor ohmic metal structure
Materials described outside the worked examples.
Platinum diffusion barrier seed layer
Pt
Titanium first metal layer
Ti
Aluminum second metal layer
Al
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
Figure 4A is the top view of the SEM image of an embodiment of the ohmic metal structure for GaN device of the present invention.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
Breakdown voltage of conventional GaN FET with Ti/Al/Ni/Au ohmic metal | 120 V | — |
Related documents with shared materials, methods, properties, or citations.
Conventional GaN FET ohmic metal (Ti/Al/Ni/Au)
p semiconductor structure layer
GaN p semiconductor structure layer
GaN
AlGaN p semiconductor structure layer
AlGaN
Third metal layer
Gold fourth metal layer
Au
Conventional Ni/Ti/Mo third metal layer
Figure 4B is the partial enlarged view of the SEM image of the embodiment of
Figure 4C is the partial enlarged view of the SEM image of the embodiment of
Figure 4D is the cross-sectional view of the TEM image of another embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 4E is the partial enlarged view of the SEM image of the white block region of the embodiment of
Figure 6A is the top view of the SEM image of an embodiment of the ohmic metal (Ti/A l/Ti/Au) for GaN device of conventional technology.
Figure 6B is the partial enlarged view of the SEM image of the embodiment of
Figure 6C is the partial enlarged view of the SEM image of the embodiment of
Figure 7A is the top view of the SEM image of an embodiment of the ohmic metal (Ti/A l/Mo/Au) for GaN device of conventional technology.
Figure 7B is the cross-sectional view of the TEM image along the broken line of the arrow of the embodiment of
Figure 7C is the partial enlarged view of the TEM image of the block R region of the embodiment of
Figure 7D is the partial enlarged view of the TEM image of the block R 1 region of the embodiment of
Figure 7E is the partial enlarged view of the TEM image of the block R₂ region of the embodiment of
Figure 7F is the partial enlarged view of the TEM image of the block R₃ region of the embodiment of
Figure 7G is the partial enlarged view of the TEM image of the block R₄ region of the embodiment of
Conventional GaN FET ohmic metal (Ti/Al/Ni/Au)
p semiconductor structure layer
GaN p semiconductor structure layer
GaN
AlGaN p semiconductor structure layer
AlGaN
Third metal layer
Gold fourth metal layer
Au
Conventional Ni/Ti/Mo third metal layer
Figure 4B is the partial enlarged view of the SEM image of the embodiment of
Figure 4C is the partial enlarged view of the SEM image of the embodiment of
Figure 4D is the cross-sectional view of the TEM image of another embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 4E is the partial enlarged view of the SEM image of the white block region of the embodiment of
Figure 6A is the top view of the SEM image of an embodiment of the ohmic metal (Ti/A l/Ti/Au) for GaN device of conventional technology.
Figure 6B is the partial enlarged view of the SEM image of the embodiment of
Figure 6C is the partial enlarged view of the SEM image of the embodiment of
Figure 7A is the top view of the SEM image of an embodiment of the ohmic metal (Ti/A l/Mo/Au) for GaN device of conventional technology.
Figure 7B is the cross-sectional view of the TEM image along the broken line of the arrow of the embodiment of
Figure 7C is the partial enlarged view of the TEM image of the block R region of the embodiment of
Figure 7D is the partial enlarged view of the TEM image of the block R 1 region of the embodiment of
Figure 7E is the partial enlarged view of the TEM image of the block R₂ region of the embodiment of
Figure 7F is the partial enlarged view of the TEM image of the block R₃ region of the embodiment of
Figure 7G is the partial enlarged view of the TEM image of the block R₄ region of the embodiment of
Conventional GaN FET ohmic metal (Ti/Al/Ni/Au)
p semiconductor structure layer
GaN p semiconductor structure layer
GaN
AlGaN p semiconductor structure layer
AlGaN
Third metal layer
Gold fourth metal layer
Au
Conventional Ni/Ti/Mo third metal layer
Figure 4B is the partial enlarged view of the SEM image of the embodiment of
Figure 4C is the partial enlarged view of the SEM image of the embodiment of
Figure 4D is the cross-sectional view of the TEM image of another embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 4E is the partial enlarged view of the SEM image of the white block region of the embodiment of
Figure 6A is the top view of the SEM image of an embodiment of the ohmic metal (Ti/A l/Ti/Au) for GaN device of conventional technology.
Figure 6B is the partial enlarged view of the SEM image of the embodiment of
Figure 6C is the partial enlarged view of the SEM image of the embodiment of
Figure 7A is the top view of the SEM image of an embodiment of the ohmic metal (Ti/A l/Mo/Au) for GaN device of conventional technology.
Figure 7B is the cross-sectional view of the TEM image along the broken line of the arrow of the embodiment of
Figure 7C is the partial enlarged view of the TEM image of the block R region of the embodiment of
Figure 7D is the partial enlarged view of the TEM image of the block R 1 region of the embodiment of
Figure 7E is the partial enlarged view of the TEM image of the block R₂ region of the embodiment of
Figure 7F is the partial enlarged view of the TEM image of the block R₃ region of the embodiment of
Figure 7G is the partial enlarged view of the TEM image of the block R₄ region of the embodiment of
Conventional GaN FET ohmic metal (Ti/Al/Ni/Au)
p semiconductor structure layer
GaN p semiconductor structure layer
GaN
AlGaN p semiconductor structure layer
AlGaN
Third metal layer
Gold fourth metal layer
Au
Conventional Ni/Ti/Mo third metal layer
Figure 4B is the partial enlarged view of the SEM image of the embodiment of
Figure 4C is the partial enlarged view of the SEM image of the embodiment of
Figure 4D is the cross-sectional view of the TEM image of another embodiment of the ohmic metal structure for GaN device of the present invention.
Figure 4E is the partial enlarged view of the SEM image of the white block region of the embodiment of
Figure 6A is the top view of the SEM image of an embodiment of the ohmic metal (Ti/A l/Ti/Au) for GaN device of conventional technology.
Figure 6B is the partial enlarged view of the SEM image of the embodiment of
Figure 6C is the partial enlarged view of the SEM image of the embodiment of
Figure 7A is the top view of the SEM image of an embodiment of the ohmic metal (Ti/A l/Mo/Au) for GaN device of conventional technology.
Figure 7B is the cross-sectional view of the TEM image along the broken line of the arrow of the embodiment of
Figure 7C is the partial enlarged view of the TEM image of the block R region of the embodiment of
Figure 7D is the partial enlarged view of the TEM image of the block R 1 region of the embodiment of
Figure 7E is the partial enlarged view of the TEM image of the block R₂ region of the embodiment of
Figure 7F is the partial enlarged view of the TEM image of the block R₃ region of the embodiment of
Figure 7G is the partial enlarged view of the TEM image of the block R₄ region of the embodiment of