Patent
Atlas literature
Patent
US 9,397,186Patent drawings and their descriptions. Click a drawing to enlarge it.
FIGS. 1-6 are simplified cross-sectional diagrams illustrating a process flow for fabrication of an MPS diode according to a first embodiment of the present …
FIG. 2 illustrates the removal of portions of the first GaN epitaxial layer 101 to form openings 201 in the first GaN epitaxial layer 101. As illustrated, the …
FIG. 3. The structural properties, such as dopant concentrations and thicknesses, can vary from those in embodiments shown in
FIG. 4 illustrates the formation of epitaxial regions 401, or structures, in the openings 201 the first GaN epitaxial layer 101. These epitaxial regions 401, …
FIG. 5 illustrates the formation of a contact metal structure 501 on some of the regions 301, including the regions 301-1 and a portion of regions 301-2, as …
FIG. 6 illustrates the formation of a back metal structure 601 on the bottom of GaN substrate 100. The back metal structure 601 can be one or more layers of …
FIG. 7. Thus, as illustrated in
FIG. 8) and the sidewalls between the extensions protruding from epitaxial layer 101. Because the sidewalls above height 710 are fabricated by etching into …
FIG. 9 illustrates the formation of a back metal structure 901 below the GaN substrate 100. As with the previous embodiment shown in
FIG. 10 is a simplified flowchart illustrating a method of fabricating an MPS diode according to an embodiment of the present invention. The method 1000 is …
FIG. 11 is a simplified flowchart illustrating a method of fabricating an MPS diode according to another embodiment of the present invention. DETAILED …
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 fabricating a merged P-i-N Schottky (MPS) diode in gallium nitride (GaN) based materials, the method comprising: providing a n-type GaN-based substrate having a first surface and a second surface; forming an n-type GaN-based epitaxial layer coupled to the first surface of the n-type GaN-based substrate; removing a portion of the n-type GaN-based epitaxial layer to form a plurality of protrusions extending to a predetermined distance from the first surface of the GaN-based substrate; forming a p-type GaN-based epitaxial layer using a blanket regrowth process, wherein the p-type GaN-based epitaxial layer is lattice matched with the n-type GaN-based epitaxial layer; removing a portion of the p-type GaN-based epitaxial layer to expose surfaces of the n-type GaN-based epitaxial layer, the exposed surfaces having p-type GaN-based regions disposed therebetween; forming a first metallic structure electrically coupled to the exposed surfaces of the n-type GaN-based epitaxial layer and the p-type GaN-based regions, wherein a Schottky contact is formed between the first metallic structure and the exposed surfaces of the n-type GaN-based epitaxial layer; and forming a second metallic structure electrically coupled to the second surface of the n-type GaN-based substrate. withdrawn
The method of claim 1 wherein the exposed surfaces of the n-type GaN-based epitaxial layer and upper surfaces of the p-type GaN-based regions are substantially coplanar. withdrawn
The method of claim 1 wherein an ohmic contact is formed between the first metallic structure and the p-type GaN-based regions. withdrawn
The method of claim 1 wherein removing a portion of the n- type GaN-based epitaxial layer comprises: masking portions of the n-type GaN-based epitaxial layer; etching unmasked portions of the n-type GaN-based epitaxial layer; and forming a plurality of recessed regions extending to a predetermined depth into the n-type GaN-based epitaxial layer, thereby forming the plurality of protrusions. withdrawn
The method of claim 1 wherein the n-type GaN-based substrate is characterized by a first n-type dopant concentration and the n-type GaN-based epitaxial layer is characterized by a second n-type dopant concentration less than the first n-type dopant concentration. withdrawn
The method of claim 1 wherein at least one of the p-type GaN-based regions is configured to provide edge termination to the MPS diode. withdrawn
The method of claim 1 wherein at least one of the p-type GaN-based regions is configured to provide a junction termination extension to the MPS diode. withdrawn
A method for fabricating an MPS diode, the method comprising: providing a I II -nitride substrate of a first conductivity type having a first surface and a second surface opposing the first surface; forming a first I II -nitride epitaxial layer of the first conductivity type coupled to the first surface of the I II -nitride substrate, the first I II -nitride epitaxial layer having a first surface adjacent the first surface of the I II -nitride substrate and a second surface opposing the first surface; forming a mask pattern coupled to the second surface of the first I II -nitride epitaxial layer to define etch areas; etching the etch areas to form a plurality of recessed regions extending to a predetermined depth into the first I II -nitride epitaxial layer; Page 4 of 9 App l. No. 14/602,125 PATENT Amdt. dated Response to Office Action of regrowing a second I II -nitride epitaxial layer that fills the recessed regions and extends to a predetermined height from the second surface of the first III -nitride epitaxial layer, wherein the second I II -nitride epitaxial layer is lattice matched with the first I II -nitride epitaxial layer; forming a second mask pattern coupled to the second III -nitride epitaxial layer to define second etch areas; etching the second etch areas to define a plurality of regrown regions extending in a direction normal to the second surface of the first I II -nitride epitaxial layer and to expose a plurality of portions of the first I II -nitride epitaxial layer; forming a first metallic structure electrically coupled to one or more of the plurality of regrown regions and one or more of the exposed portions of the first I II -nitride epitaxial layer; and forming a second metallic structure electrically coupled to the second surface of the I II -nitride substrate.
The method of claim 8 wherein the first metallic structure comprises a Schottky contact to the exposed portions of the first I II -nitride epitaxial layer and an ohmic contact to the one or more of the plurality of regrown regions.
The method of claim 8 wherein the exposed plurality of portions of the first I II -nitride epitaxial layer are individually interspersed between the plurality of regrown regions.
The method of claim 8 wherein a lateral width of each of the plurality of regrown regions measured in the plane of the second surface of the first III -nitride epitaxial layer is greater than a lateral width of each of the exposed plurality of portions of the first I II -nitride epitaxial layer measured in the plane of the second surface of the first I II -nitride epitaxial layer.
The method of claim 8 wherein the I II -nitride substrate is characterized by a first dopant concentration and the first I II -nitride epitaxial layer is characterized by a second n-type dopant concentration less than the first dopant concentration.
The method of claim 8 wherein at least one of the plurality of regrown regions is configured to provide edge termination to a semiconductor device.
The method of claim 8 wherein at least one of the plurality of regrown regions is configured to provide a junction termination extension to a semiconductor device.
The method of claim 8 wherein: the first I II -nitride epitaxial layer is G aN; and the first conductivity type is n-type. withdrawn
The method of claim 8 wherein: each of the plurality of regrown regions comprises a first section and a second section; the first section, of each of the plurality of I II -nitride regions, is disposed between portions of the first I II -nitride epitaxial layer; and the second section, of each of the plurality of I II -nitride regions, extends beyond a height of portions of the first I II -nitride epitaxial layer and has a width greater than a width of a corresponding first section such that the second section overhangs the corresponding first section. withdrawn
The method of claim 8 wherein the first I II -nitride epitaxial layer is formed to have a thickness measured in a direction normal to the first surface of the III- nitride substrate, and the thickness is between 0.5 microns and 100 microns. withdrawn
The method of claim 8 wherein: Page 6 of 9 App l. No. 14/602,125 PATENT Am dt. dated Response to Office Action of the plurality of regrown regions have a doping concentration in a range from 10 17 to 2 x 1020 cm⁻³; the first I II -nitride epitaxial layer has a doping concentration in a range from 10 17 to 2 x 1020 cm- 3; and the I II -nitride substrate has a doping concentration in a range from 10 " to 1 x 10 2 0 -3 cm 7 Page 7 of 9 withdrawn
Layer stacks claimed or described, ordered top of device to substrate.
Merged P-i-N Schottky (MPS) diode in GaN-based materials
Materials described outside the worked examples.
n-type GaN-based epitaxial layer
GaN
first III-nitride epitaxial layer (first conductivity type)
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 7. Thus, as illustrated in
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
Voltage | ≥ 1 V | — |
Thickness |
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Patent
Atlas literature
Patent
US 9,397,186Patent drawings and their descriptions. Click a drawing to enlarge it.
FIGS. 1-6 are simplified cross-sectional diagrams illustrating a process flow for fabrication of an MPS diode according to a first embodiment of the present …
FIG. 2 illustrates the removal of portions of the first GaN epitaxial layer 101 to form openings 201 in the first GaN epitaxial layer 101. As illustrated, the …
FIG. 3. The structural properties, such as dopant concentrations and thicknesses, can vary from those in embodiments shown in
FIG. 4 illustrates the formation of epitaxial regions 401, or structures, in the openings 201 the first GaN epitaxial layer 101. These epitaxial regions 401, …
FIG. 5 illustrates the formation of a contact metal structure 501 on some of the regions 301, including the regions 301-1 and a portion of regions 301-2, as …
FIG. 6 illustrates the formation of a back metal structure 601 on the bottom of GaN substrate 100. The back metal structure 601 can be one or more layers of …
FIG. 7. Thus, as illustrated in
FIG. 8) and the sidewalls between the extensions protruding from epitaxial layer 101. Because the sidewalls above height 710 are fabricated by etching into …
FIG. 9 illustrates the formation of a back metal structure 901 below the GaN substrate 100. As with the previous embodiment shown in
FIG. 10 is a simplified flowchart illustrating a method of fabricating an MPS diode according to an embodiment of the present invention. The method 1000 is …
FIG. 11 is a simplified flowchart illustrating a method of fabricating an MPS diode according to another embodiment of the present invention. DETAILED …
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 fabricating a merged P-i-N Schottky (MPS) diode in gallium nitride (GaN) based materials, the method comprising: providing a n-type GaN-based substrate having a first surface and a second surface; forming an n-type GaN-based epitaxial layer coupled to the first surface of the n-type GaN-based substrate; removing a portion of the n-type GaN-based epitaxial layer to form a plurality of protrusions extending to a predetermined distance from the first surface of the GaN-based substrate; forming a p-type GaN-based epitaxial layer using a blanket regrowth process, wherein the p-type GaN-based epitaxial layer is lattice matched with the n-type GaN-based epitaxial layer; removing a portion of the p-type GaN-based epitaxial layer to expose surfaces of the n-type GaN-based epitaxial layer, the exposed surfaces having p-type GaN-based regions disposed therebetween; forming a first metallic structure electrically coupled to the exposed surfaces of the n-type GaN-based epitaxial layer and the p-type GaN-based regions, wherein a Schottky contact is formed between the first metallic structure and the exposed surfaces of the n-type GaN-based epitaxial layer; and forming a second metallic structure electrically coupled to the second surface of the n-type GaN-based substrate. withdrawn
The method of claim 1 wherein the exposed surfaces of the n-type GaN-based epitaxial layer and upper surfaces of the p-type GaN-based regions are substantially coplanar. withdrawn
The method of claim 1 wherein an ohmic contact is formed between the first metallic structure and the p-type GaN-based regions. withdrawn
The method of claim 1 wherein removing a portion of the n- type GaN-based epitaxial layer comprises: masking portions of the n-type GaN-based epitaxial layer; etching unmasked portions of the n-type GaN-based epitaxial layer; and forming a plurality of recessed regions extending to a predetermined depth into the n-type GaN-based epitaxial layer, thereby forming the plurality of protrusions. withdrawn
The method of claim 1 wherein the n-type GaN-based substrate is characterized by a first n-type dopant concentration and the n-type GaN-based epitaxial layer is characterized by a second n-type dopant concentration less than the first n-type dopant concentration. withdrawn
The method of claim 1 wherein at least one of the p-type GaN-based regions is configured to provide edge termination to the MPS diode. withdrawn
The method of claim 1 wherein at least one of the p-type GaN-based regions is configured to provide a junction termination extension to the MPS diode. withdrawn
A method for fabricating an MPS diode, the method comprising: providing a I II -nitride substrate of a first conductivity type having a first surface and a second surface opposing the first surface; forming a first I II -nitride epitaxial layer of the first conductivity type coupled to the first surface of the I II -nitride substrate, the first I II -nitride epitaxial layer having a first surface adjacent the first surface of the I II -nitride substrate and a second surface opposing the first surface; forming a mask pattern coupled to the second surface of the first I II -nitride epitaxial layer to define etch areas; etching the etch areas to form a plurality of recessed regions extending to a predetermined depth into the first I II -nitride epitaxial layer; Page 4 of 9 App l. No. 14/602,125 PATENT Amdt. dated Response to Office Action of regrowing a second I II -nitride epitaxial layer that fills the recessed regions and extends to a predetermined height from the second surface of the first III -nitride epitaxial layer, wherein the second I II -nitride epitaxial layer is lattice matched with the first I II -nitride epitaxial layer; forming a second mask pattern coupled to the second III -nitride epitaxial layer to define second etch areas; etching the second etch areas to define a plurality of regrown regions extending in a direction normal to the second surface of the first I II -nitride epitaxial layer and to expose a plurality of portions of the first I II -nitride epitaxial layer; forming a first metallic structure electrically coupled to one or more of the plurality of regrown regions and one or more of the exposed portions of the first I II -nitride epitaxial layer; and forming a second metallic structure electrically coupled to the second surface of the I II -nitride substrate.
The method of claim 8 wherein the first metallic structure comprises a Schottky contact to the exposed portions of the first I II -nitride epitaxial layer and an ohmic contact to the one or more of the plurality of regrown regions.
The method of claim 8 wherein the exposed plurality of portions of the first I II -nitride epitaxial layer are individually interspersed between the plurality of regrown regions.
The method of claim 8 wherein a lateral width of each of the plurality of regrown regions measured in the plane of the second surface of the first III -nitride epitaxial layer is greater than a lateral width of each of the exposed plurality of portions of the first I II -nitride epitaxial layer measured in the plane of the second surface of the first I II -nitride epitaxial layer.
The method of claim 8 wherein the I II -nitride substrate is characterized by a first dopant concentration and the first I II -nitride epitaxial layer is characterized by a second n-type dopant concentration less than the first dopant concentration.
The method of claim 8 wherein at least one of the plurality of regrown regions is configured to provide edge termination to a semiconductor device.
The method of claim 8 wherein at least one of the plurality of regrown regions is configured to provide a junction termination extension to a semiconductor device.
The method of claim 8 wherein: the first I II -nitride epitaxial layer is G aN; and the first conductivity type is n-type. withdrawn
The method of claim 8 wherein: each of the plurality of regrown regions comprises a first section and a second section; the first section, of each of the plurality of I II -nitride regions, is disposed between portions of the first I II -nitride epitaxial layer; and the second section, of each of the plurality of I II -nitride regions, extends beyond a height of portions of the first I II -nitride epitaxial layer and has a width greater than a width of a corresponding first section such that the second section overhangs the corresponding first section. withdrawn
The method of claim 8 wherein the first I II -nitride epitaxial layer is formed to have a thickness measured in a direction normal to the first surface of the III- nitride substrate, and the thickness is between 0.5 microns and 100 microns. withdrawn
The method of claim 8 wherein: Page 6 of 9 App l. No. 14/602,125 PATENT Am dt. dated Response to Office Action of the plurality of regrown regions have a doping concentration in a range from 10 17 to 2 x 1020 cm⁻³; the first I II -nitride epitaxial layer has a doping concentration in a range from 10 17 to 2 x 1020 cm- 3; and the I II -nitride substrate has a doping concentration in a range from 10 " to 1 x 10 2 0 -3 cm 7 Page 7 of 9 withdrawn
Layer stacks claimed or described, ordered top of device to substrate.
Merged P-i-N Schottky (MPS) diode in GaN-based materials
Materials described outside the worked examples.
n-type GaN-based epitaxial layer
GaN
first III-nitride epitaxial layer (first conductivity type)
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 7. Thus, as illustrated in
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
Voltage | ≥ 1 V | — |
Thickness |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 9,397,186Patent drawings and their descriptions. Click a drawing to enlarge it.
FIGS. 1-6 are simplified cross-sectional diagrams illustrating a process flow for fabrication of an MPS diode according to a first embodiment of the present …
FIG. 2 illustrates the removal of portions of the first GaN epitaxial layer 101 to form openings 201 in the first GaN epitaxial layer 101. As illustrated, the …
FIG. 3. The structural properties, such as dopant concentrations and thicknesses, can vary from those in embodiments shown in
FIG. 4 illustrates the formation of epitaxial regions 401, or structures, in the openings 201 the first GaN epitaxial layer 101. These epitaxial regions 401, …
FIG. 5 illustrates the formation of a contact metal structure 501 on some of the regions 301, including the regions 301-1 and a portion of regions 301-2, as …
FIG. 6 illustrates the formation of a back metal structure 601 on the bottom of GaN substrate 100. The back metal structure 601 can be one or more layers of …
FIG. 7. Thus, as illustrated in
FIG. 8) and the sidewalls between the extensions protruding from epitaxial layer 101. Because the sidewalls above height 710 are fabricated by etching into …
FIG. 9 illustrates the formation of a back metal structure 901 below the GaN substrate 100. As with the previous embodiment shown in
FIG. 10 is a simplified flowchart illustrating a method of fabricating an MPS diode according to an embodiment of the present invention. The method 1000 is …
FIG. 11 is a simplified flowchart illustrating a method of fabricating an MPS diode according to another embodiment of the present invention. DETAILED …
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 fabricating a merged P-i-N Schottky (MPS) diode in gallium nitride (GaN) based materials, the method comprising: providing a n-type GaN-based substrate having a first surface and a second surface; forming an n-type GaN-based epitaxial layer coupled to the first surface of the n-type GaN-based substrate; removing a portion of the n-type GaN-based epitaxial layer to form a plurality of protrusions extending to a predetermined distance from the first surface of the GaN-based substrate; forming a p-type GaN-based epitaxial layer using a blanket regrowth process, wherein the p-type GaN-based epitaxial layer is lattice matched with the n-type GaN-based epitaxial layer; removing a portion of the p-type GaN-based epitaxial layer to expose surfaces of the n-type GaN-based epitaxial layer, the exposed surfaces having p-type GaN-based regions disposed therebetween; forming a first metallic structure electrically coupled to the exposed surfaces of the n-type GaN-based epitaxial layer and the p-type GaN-based regions, wherein a Schottky contact is formed between the first metallic structure and the exposed surfaces of the n-type GaN-based epitaxial layer; and forming a second metallic structure electrically coupled to the second surface of the n-type GaN-based substrate. withdrawn
The method of claim 1 wherein the exposed surfaces of the n-type GaN-based epitaxial layer and upper surfaces of the p-type GaN-based regions are substantially coplanar. withdrawn
The method of claim 1 wherein an ohmic contact is formed between the first metallic structure and the p-type GaN-based regions. withdrawn
The method of claim 1 wherein removing a portion of the n- type GaN-based epitaxial layer comprises: masking portions of the n-type GaN-based epitaxial layer; etching unmasked portions of the n-type GaN-based epitaxial layer; and forming a plurality of recessed regions extending to a predetermined depth into the n-type GaN-based epitaxial layer, thereby forming the plurality of protrusions. withdrawn
The method of claim 1 wherein the n-type GaN-based substrate is characterized by a first n-type dopant concentration and the n-type GaN-based epitaxial layer is characterized by a second n-type dopant concentration less than the first n-type dopant concentration. withdrawn
The method of claim 1 wherein at least one of the p-type GaN-based regions is configured to provide edge termination to the MPS diode. withdrawn
The method of claim 1 wherein at least one of the p-type GaN-based regions is configured to provide a junction termination extension to the MPS diode. withdrawn
A method for fabricating an MPS diode, the method comprising: providing a I II -nitride substrate of a first conductivity type having a first surface and a second surface opposing the first surface; forming a first I II -nitride epitaxial layer of the first conductivity type coupled to the first surface of the I II -nitride substrate, the first I II -nitride epitaxial layer having a first surface adjacent the first surface of the I II -nitride substrate and a second surface opposing the first surface; forming a mask pattern coupled to the second surface of the first I II -nitride epitaxial layer to define etch areas; etching the etch areas to form a plurality of recessed regions extending to a predetermined depth into the first I II -nitride epitaxial layer; Page 4 of 9 App l. No. 14/602,125 PATENT Amdt. dated Response to Office Action of regrowing a second I II -nitride epitaxial layer that fills the recessed regions and extends to a predetermined height from the second surface of the first III -nitride epitaxial layer, wherein the second I II -nitride epitaxial layer is lattice matched with the first I II -nitride epitaxial layer; forming a second mask pattern coupled to the second III -nitride epitaxial layer to define second etch areas; etching the second etch areas to define a plurality of regrown regions extending in a direction normal to the second surface of the first I II -nitride epitaxial layer and to expose a plurality of portions of the first I II -nitride epitaxial layer; forming a first metallic structure electrically coupled to one or more of the plurality of regrown regions and one or more of the exposed portions of the first I II -nitride epitaxial layer; and forming a second metallic structure electrically coupled to the second surface of the I II -nitride substrate.
The method of claim 8 wherein the first metallic structure comprises a Schottky contact to the exposed portions of the first I II -nitride epitaxial layer and an ohmic contact to the one or more of the plurality of regrown regions.
The method of claim 8 wherein the exposed plurality of portions of the first I II -nitride epitaxial layer are individually interspersed between the plurality of regrown regions.
The method of claim 8 wherein a lateral width of each of the plurality of regrown regions measured in the plane of the second surface of the first III -nitride epitaxial layer is greater than a lateral width of each of the exposed plurality of portions of the first I II -nitride epitaxial layer measured in the plane of the second surface of the first I II -nitride epitaxial layer.
The method of claim 8 wherein the I II -nitride substrate is characterized by a first dopant concentration and the first I II -nitride epitaxial layer is characterized by a second n-type dopant concentration less than the first dopant concentration.
The method of claim 8 wherein at least one of the plurality of regrown regions is configured to provide edge termination to a semiconductor device.
The method of claim 8 wherein at least one of the plurality of regrown regions is configured to provide a junction termination extension to a semiconductor device.
The method of claim 8 wherein: the first I II -nitride epitaxial layer is G aN; and the first conductivity type is n-type. withdrawn
The method of claim 8 wherein: each of the plurality of regrown regions comprises a first section and a second section; the first section, of each of the plurality of I II -nitride regions, is disposed between portions of the first I II -nitride epitaxial layer; and the second section, of each of the plurality of I II -nitride regions, extends beyond a height of portions of the first I II -nitride epitaxial layer and has a width greater than a width of a corresponding first section such that the second section overhangs the corresponding first section. withdrawn
The method of claim 8 wherein the first I II -nitride epitaxial layer is formed to have a thickness measured in a direction normal to the first surface of the III- nitride substrate, and the thickness is between 0.5 microns and 100 microns. withdrawn
The method of claim 8 wherein: Page 6 of 9 App l. No. 14/602,125 PATENT Am dt. dated Response to Office Action of the plurality of regrown regions have a doping concentration in a range from 10 17 to 2 x 1020 cm⁻³; the first I II -nitride epitaxial layer has a doping concentration in a range from 10 17 to 2 x 1020 cm- 3; and the I II -nitride substrate has a doping concentration in a range from 10 " to 1 x 10 2 0 -3 cm 7 Page 7 of 9 withdrawn
Layer stacks claimed or described, ordered top of device to substrate.
Merged P-i-N Schottky (MPS) diode in GaN-based materials
Materials described outside the worked examples.
n-type GaN-based epitaxial layer
GaN
first III-nitride epitaxial layer (first conductivity type)
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 7. Thus, as illustrated in
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
Voltage | ≥ 1 V | — |
Thickness |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 9,397,186Patent drawings and their descriptions. Click a drawing to enlarge it.
FIGS. 1-6 are simplified cross-sectional diagrams illustrating a process flow for fabrication of an MPS diode according to a first embodiment of the present …
FIG. 2 illustrates the removal of portions of the first GaN epitaxial layer 101 to form openings 201 in the first GaN epitaxial layer 101. As illustrated, the …
FIG. 3. The structural properties, such as dopant concentrations and thicknesses, can vary from those in embodiments shown in
FIG. 4 illustrates the formation of epitaxial regions 401, or structures, in the openings 201 the first GaN epitaxial layer 101. These epitaxial regions 401, …
FIG. 5 illustrates the formation of a contact metal structure 501 on some of the regions 301, including the regions 301-1 and a portion of regions 301-2, as …
FIG. 6 illustrates the formation of a back metal structure 601 on the bottom of GaN substrate 100. The back metal structure 601 can be one or more layers of …
FIG. 7. Thus, as illustrated in
FIG. 8) and the sidewalls between the extensions protruding from epitaxial layer 101. Because the sidewalls above height 710 are fabricated by etching into …
FIG. 9 illustrates the formation of a back metal structure 901 below the GaN substrate 100. As with the previous embodiment shown in
FIG. 10 is a simplified flowchart illustrating a method of fabricating an MPS diode according to an embodiment of the present invention. The method 1000 is …
FIG. 11 is a simplified flowchart illustrating a method of fabricating an MPS diode according to another embodiment of the present invention. DETAILED …
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 fabricating a merged P-i-N Schottky (MPS) diode in gallium nitride (GaN) based materials, the method comprising: providing a n-type GaN-based substrate having a first surface and a second surface; forming an n-type GaN-based epitaxial layer coupled to the first surface of the n-type GaN-based substrate; removing a portion of the n-type GaN-based epitaxial layer to form a plurality of protrusions extending to a predetermined distance from the first surface of the GaN-based substrate; forming a p-type GaN-based epitaxial layer using a blanket regrowth process, wherein the p-type GaN-based epitaxial layer is lattice matched with the n-type GaN-based epitaxial layer; removing a portion of the p-type GaN-based epitaxial layer to expose surfaces of the n-type GaN-based epitaxial layer, the exposed surfaces having p-type GaN-based regions disposed therebetween; forming a first metallic structure electrically coupled to the exposed surfaces of the n-type GaN-based epitaxial layer and the p-type GaN-based regions, wherein a Schottky contact is formed between the first metallic structure and the exposed surfaces of the n-type GaN-based epitaxial layer; and forming a second metallic structure electrically coupled to the second surface of the n-type GaN-based substrate. withdrawn
The method of claim 1 wherein the exposed surfaces of the n-type GaN-based epitaxial layer and upper surfaces of the p-type GaN-based regions are substantially coplanar. withdrawn
The method of claim 1 wherein an ohmic contact is formed between the first metallic structure and the p-type GaN-based regions. withdrawn
The method of claim 1 wherein removing a portion of the n- type GaN-based epitaxial layer comprises: masking portions of the n-type GaN-based epitaxial layer; etching unmasked portions of the n-type GaN-based epitaxial layer; and forming a plurality of recessed regions extending to a predetermined depth into the n-type GaN-based epitaxial layer, thereby forming the plurality of protrusions. withdrawn
The method of claim 1 wherein the n-type GaN-based substrate is characterized by a first n-type dopant concentration and the n-type GaN-based epitaxial layer is characterized by a second n-type dopant concentration less than the first n-type dopant concentration. withdrawn
The method of claim 1 wherein at least one of the p-type GaN-based regions is configured to provide edge termination to the MPS diode. withdrawn
The method of claim 1 wherein at least one of the p-type GaN-based regions is configured to provide a junction termination extension to the MPS diode. withdrawn
A method for fabricating an MPS diode, the method comprising: providing a I II -nitride substrate of a first conductivity type having a first surface and a second surface opposing the first surface; forming a first I II -nitride epitaxial layer of the first conductivity type coupled to the first surface of the I II -nitride substrate, the first I II -nitride epitaxial layer having a first surface adjacent the first surface of the I II -nitride substrate and a second surface opposing the first surface; forming a mask pattern coupled to the second surface of the first I II -nitride epitaxial layer to define etch areas; etching the etch areas to form a plurality of recessed regions extending to a predetermined depth into the first I II -nitride epitaxial layer; Page 4 of 9 App l. No. 14/602,125 PATENT Amdt. dated Response to Office Action of regrowing a second I II -nitride epitaxial layer that fills the recessed regions and extends to a predetermined height from the second surface of the first III -nitride epitaxial layer, wherein the second I II -nitride epitaxial layer is lattice matched with the first I II -nitride epitaxial layer; forming a second mask pattern coupled to the second III -nitride epitaxial layer to define second etch areas; etching the second etch areas to define a plurality of regrown regions extending in a direction normal to the second surface of the first I II -nitride epitaxial layer and to expose a plurality of portions of the first I II -nitride epitaxial layer; forming a first metallic structure electrically coupled to one or more of the plurality of regrown regions and one or more of the exposed portions of the first I II -nitride epitaxial layer; and forming a second metallic structure electrically coupled to the second surface of the I II -nitride substrate.
The method of claim 8 wherein the first metallic structure comprises a Schottky contact to the exposed portions of the first I II -nitride epitaxial layer and an ohmic contact to the one or more of the plurality of regrown regions.
The method of claim 8 wherein the exposed plurality of portions of the first I II -nitride epitaxial layer are individually interspersed between the plurality of regrown regions.
The method of claim 8 wherein a lateral width of each of the plurality of regrown regions measured in the plane of the second surface of the first III -nitride epitaxial layer is greater than a lateral width of each of the exposed plurality of portions of the first I II -nitride epitaxial layer measured in the plane of the second surface of the first I II -nitride epitaxial layer.
The method of claim 8 wherein the I II -nitride substrate is characterized by a first dopant concentration and the first I II -nitride epitaxial layer is characterized by a second n-type dopant concentration less than the first dopant concentration.
The method of claim 8 wherein at least one of the plurality of regrown regions is configured to provide edge termination to a semiconductor device.
The method of claim 8 wherein at least one of the plurality of regrown regions is configured to provide a junction termination extension to a semiconductor device.
The method of claim 8 wherein: the first I II -nitride epitaxial layer is G aN; and the first conductivity type is n-type. withdrawn
The method of claim 8 wherein: each of the plurality of regrown regions comprises a first section and a second section; the first section, of each of the plurality of I II -nitride regions, is disposed between portions of the first I II -nitride epitaxial layer; and the second section, of each of the plurality of I II -nitride regions, extends beyond a height of portions of the first I II -nitride epitaxial layer and has a width greater than a width of a corresponding first section such that the second section overhangs the corresponding first section. withdrawn
The method of claim 8 wherein the first I II -nitride epitaxial layer is formed to have a thickness measured in a direction normal to the first surface of the III- nitride substrate, and the thickness is between 0.5 microns and 100 microns. withdrawn
The method of claim 8 wherein: Page 6 of 9 App l. No. 14/602,125 PATENT Am dt. dated Response to Office Action of the plurality of regrown regions have a doping concentration in a range from 10 17 to 2 x 1020 cm⁻³; the first I II -nitride epitaxial layer has a doping concentration in a range from 10 17 to 2 x 1020 cm- 3; and the I II -nitride substrate has a doping concentration in a range from 10 " to 1 x 10 2 0 -3 cm 7 Page 7 of 9 withdrawn
Layer stacks claimed or described, ordered top of device to substrate.
Merged P-i-N Schottky (MPS) diode in GaN-based materials
Materials described outside the worked examples.
n-type GaN-based epitaxial layer
GaN
first III-nitride epitaxial layer (first conductivity type)
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 7. Thus, as illustrated in
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
Voltage | ≥ 1 V | — |
Thickness |
Related documents with shared materials, methods, properties, or citations.
second III-nitride epitaxial layer/regrown regions
III-nitride substrate
FIG. 8) and the sidewalls between the extensions protruding from epitaxial layer 101. Because the sidewalls above height 710 are fabricated by etching into …
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Thickness | 0.5–100 µm | — |
Thickness | 5–100 µm | — |
Thickness | 0–3 cm | — |
second III-nitride epitaxial layer/regrown regions
III-nitride substrate
FIG. 8) and the sidewalls between the extensions protruding from epitaxial layer 101. Because the sidewalls above height 710 are fabricated by etching into …
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Thickness | 0.5–100 µm | — |
Thickness | 5–100 µm | — |
Thickness | 0–3 cm | — |
second III-nitride epitaxial layer/regrown regions
III-nitride substrate
FIG. 8) and the sidewalls between the extensions protruding from epitaxial layer 101. Because the sidewalls above height 710 are fabricated by etching into …
| — |
Thickness | 0.5–100 µm | — |
Thickness | 5–100 µm | — |
Thickness | 0–3 cm | — |
second III-nitride epitaxial layer/regrown regions
III-nitride substrate
FIG. 8) and the sidewalls between the extensions protruding from epitaxial layer 101. Because the sidewalls above height 710 are fabricated by etching into …
| — |
Thickness | 0.5–100 µm | — |
Thickness | 5–100 µm | — |
Thickness | 0–3 cm | — |
