Patent
US 9,490,356Growth of High-Performance III-Nitride Transistor Passivation Layer for GaN Electronics
Andrew D. Koehler, Travis J. Anderson, Karl D. Hobart, Francis J. Kub
US
Copyright © 2026 Matter42. All rights reserved.
Patent
Atlas literature
Patent
US 9,490,356Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 is a block diagram illustrating an unpassivated AlGaN/GaN HEMT in accordance with the prior art. [021]
FIG. 2 provides a flow chart outlining exemplary process steps in a method for fabricating a I II -nitride passivation layer on an AlGaN/GaN HEMT device using …
FIGS. 3A and 3B are block diagrams illustrating embodiments of a passivated AlGaN/GaN HEMT that includes a I II -nitride passivation layer formed by ALE in …
FIG. 4 B) curves of AlGaN/GaN HEMTs having a SiN X passivation layer in accordance with the p ri or art and an A l N passivation layer formed by ALE in …
FIG. 5 is a plot showing non-recoverable off-state breakdown during drain voltage sweep at a rate of 2V/sec for AlGaN/GaN HEMTs having a conventional SiN X …
FIG. 6 is a plot showing the change in dynamic R O N f o r va rious quie sc ent p o int drain voltage stress for AlGaN/GaN HEMTs having a conventional SiN X …
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 forming a passivated AlGaN/GaN HEMT, comprising: forming a GaN buffer/channel layer on a substrate; forming an AlGaN barrier layer on the GaN buffer/channel layer to form an AlGaN/GaN structure; etching mesa isolation trenches in the AlGaN barrier layer to define an area on an upper surface of the barrier layer on which a source, a drain, and a gate element of a HEMT are to be formed; subjecting the AlGaN/GaN structure to an ex situ cleaning to prepare the AlGaN/GaN structure for growth of a I II -nitride passivation layer thereon; placing the cleaned AlGaN/GaN structure into an atomic layer epitaxy (ALE) reaction chamber and subjecting the AlGaN/GaN structure to an in situ cleaning to further prepare the AlGaN/GaN structure for growth of the I II -nitride passivation layer thereon; growing the I II -nitride passivation layer on an upper surface of the AlGaN barrier layer by ALE at a temperature of about 300 ° C to about 850 ° C to form a passivated AlGaN/GaN structure; etching the I II -nitride passivation layer to expose portions of the AlGaN surface for deposition of materials for source, a gate, and a drain electrodes; and forming the source, gate, and drain electrodes on the portions of the AlGaN surface defined by the etched passivation layer.
The method according to claim 1, wherein the I II -nitride passivation layer is grown to a thickness of about 0.5 nm to about 300 nm.
The method according to claim 1, wherein the I II -nitride passivation material is A lN.
The method according to claim 1, wherein the I II -nitride passivation layer is etched in a Cl 2 plasma.
The method according to claim 1, wherein the I II -nitride passivation layer is etched in a heated AZ₄₀₀K developer.
The method according to claim 1, wherein the gate metal is a Ni/Au Schottky metal.
The method according to claim 1, wherein the gate metal is deposited by electron beam evaporation.
The method according to claim 1, wherein the gate metal is patterned by liftoff.
The method according to claim 1, further comprising depositing a layer of dielectric material on the AlGaN/GaN HEMT before growth of the I II -nitride passivation layer thereon.
The method according to claim 11, wherein the I II -nitride passivation layer comprises a relaxed I II -nitride material.
The method according to claim 11, wherein the I II -nitride passivation layer comprises a nonrelaxed I II -nitride material.
A method for forming a passivated AlGaN/GaN HEMT, comprising: forming a GaN buffer/channel layer on a substrate; forming an AlGaN barrier layer on the GaN buffer/channel layer to form an AlGaN/GaN structure; etching mesa isolation trenches in the AlGaN barrier layer to define an area on an upper surface of the barrier layer on which a source, a drain, and a gate element of a HEMT are to be formed; forming the source and drain elements on the surface of the AlGaN barrier layer; subjecting the AlGaN/GaN structure to an ex situ cleaning to prepare the AlGaN/GaN structure for growth of a I II -nitride passivation layer thereon; placing the cleaned AlGaN/GaN structure into an atomic layer epitaxy (ALE) reaction chamber and subjecting the AlGaN/GaN structure to an in situ cleaning to further prepare the AlGaN/GaN structure for growth of the I II -nitride passivation layer thereon; growing the I II -nitride passivation layer on an upper surface of the AlGaN barrier layer by ALE at a temperature of about 300 ° C to about 850 ° C to form a passivated AlGaN/GaN structure; etching the I II -nitride passivation layer to expose a portions of the AlGaN surface for deposition of a gate electrode thereon; and forming gate electrode on the portions of the AlGaN surface defined by the etched passivation layer.
The method according to claim 12, wherein the I II -nitride passivation layer comprises a relaxed I II -nitride material.
The method according to claim 12, wherein the I II -nitride passivation layer comprises a nonrelaxed I II -nitride material.
The method according to claim 12, wherein
The method according to claim 12, wherein thickness of about 0.5 nm to about 300 nm.
The method according to claim 12, further material on the AlGaN/GaN HEMT before growth Page 22 of 23 the I II -nitride passivation material is A lN. the I II -nitride passivation layer is grown to a comprising depositing a layer of dielectric of the I II -nitride passivation layer thereon.
Layer stacks claimed or described, ordered top of device to substrate.
passivated AlGaN/GaN HEMT
Materials described outside the worked examples.
III-nitride passivation layer
GaN buffer/channel layer
GaN
Additional fabrication and treatment steps described in the patent.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
Temperature | 300–850 °C | — |
Temperature |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 9,490,356Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 is a block diagram illustrating an unpassivated AlGaN/GaN HEMT in accordance with the prior art. [021]
FIG. 2 provides a flow chart outlining exemplary process steps in a method for fabricating a I II -nitride passivation layer on an AlGaN/GaN HEMT device using …
FIGS. 3A and 3B are block diagrams illustrating embodiments of a passivated AlGaN/GaN HEMT that includes a I II -nitride passivation layer formed by ALE in …
FIG. 4 B) curves of AlGaN/GaN HEMTs having a SiN X passivation layer in accordance with the p ri or art and an A l N passivation layer formed by ALE in …
FIG. 5 is a plot showing non-recoverable off-state breakdown during drain voltage sweep at a rate of 2V/sec for AlGaN/GaN HEMTs having a conventional SiN X …
FIG. 6 is a plot showing the change in dynamic R O N f o r va rious quie sc ent p o int drain voltage stress for AlGaN/GaN HEMTs having a conventional SiN X …
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 forming a passivated AlGaN/GaN HEMT, comprising: forming a GaN buffer/channel layer on a substrate; forming an AlGaN barrier layer on the GaN buffer/channel layer to form an AlGaN/GaN structure; etching mesa isolation trenches in the AlGaN barrier layer to define an area on an upper surface of the barrier layer on which a source, a drain, and a gate element of a HEMT are to be formed; subjecting the AlGaN/GaN structure to an ex situ cleaning to prepare the AlGaN/GaN structure for growth of a I II -nitride passivation layer thereon; placing the cleaned AlGaN/GaN structure into an atomic layer epitaxy (ALE) reaction chamber and subjecting the AlGaN/GaN structure to an in situ cleaning to further prepare the AlGaN/GaN structure for growth of the I II -nitride passivation layer thereon; growing the I II -nitride passivation layer on an upper surface of the AlGaN barrier layer by ALE at a temperature of about 300 ° C to about 850 ° C to form a passivated AlGaN/GaN structure; etching the I II -nitride passivation layer to expose portions of the AlGaN surface for deposition of materials for source, a gate, and a drain electrodes; and forming the source, gate, and drain electrodes on the portions of the AlGaN surface defined by the etched passivation layer.
The method according to claim 1, wherein the I II -nitride passivation layer is grown to a thickness of about 0.5 nm to about 300 nm.
The method according to claim 1, wherein the I II -nitride passivation material is A lN.
The method according to claim 1, wherein the I II -nitride passivation layer is etched in a Cl 2 plasma.
The method according to claim 1, wherein the I II -nitride passivation layer is etched in a heated AZ₄₀₀K developer.
The method according to claim 1, wherein the gate metal is a Ni/Au Schottky metal.
The method according to claim 1, wherein the gate metal is deposited by electron beam evaporation.
The method according to claim 1, wherein the gate metal is patterned by liftoff.
The method according to claim 1, further comprising depositing a layer of dielectric material on the AlGaN/GaN HEMT before growth of the I II -nitride passivation layer thereon.
The method according to claim 11, wherein the I II -nitride passivation layer comprises a relaxed I II -nitride material.
The method according to claim 11, wherein the I II -nitride passivation layer comprises a nonrelaxed I II -nitride material.
A method for forming a passivated AlGaN/GaN HEMT, comprising: forming a GaN buffer/channel layer on a substrate; forming an AlGaN barrier layer on the GaN buffer/channel layer to form an AlGaN/GaN structure; etching mesa isolation trenches in the AlGaN barrier layer to define an area on an upper surface of the barrier layer on which a source, a drain, and a gate element of a HEMT are to be formed; forming the source and drain elements on the surface of the AlGaN barrier layer; subjecting the AlGaN/GaN structure to an ex situ cleaning to prepare the AlGaN/GaN structure for growth of a I II -nitride passivation layer thereon; placing the cleaned AlGaN/GaN structure into an atomic layer epitaxy (ALE) reaction chamber and subjecting the AlGaN/GaN structure to an in situ cleaning to further prepare the AlGaN/GaN structure for growth of the I II -nitride passivation layer thereon; growing the I II -nitride passivation layer on an upper surface of the AlGaN barrier layer by ALE at a temperature of about 300 ° C to about 850 ° C to form a passivated AlGaN/GaN structure; etching the I II -nitride passivation layer to expose a portions of the AlGaN surface for deposition of a gate electrode thereon; and forming gate electrode on the portions of the AlGaN surface defined by the etched passivation layer.
The method according to claim 12, wherein the I II -nitride passivation layer comprises a relaxed I II -nitride material.
The method according to claim 12, wherein the I II -nitride passivation layer comprises a nonrelaxed I II -nitride material.
The method according to claim 12, wherein
The method according to claim 12, wherein thickness of about 0.5 nm to about 300 nm.
The method according to claim 12, further material on the AlGaN/GaN HEMT before growth Page 22 of 23 the I II -nitride passivation material is A lN. the I II -nitride passivation layer is grown to a comprising depositing a layer of dielectric of the I II -nitride passivation layer thereon.
Layer stacks claimed or described, ordered top of device to substrate.
passivated AlGaN/GaN HEMT
Materials described outside the worked examples.
III-nitride passivation layer
GaN buffer/channel layer
GaN
Additional fabrication and treatment steps described in the patent.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
Temperature | 300–850 °C | — |
Temperature |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 9,490,356Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 is a block diagram illustrating an unpassivated AlGaN/GaN HEMT in accordance with the prior art. [021]
FIG. 2 provides a flow chart outlining exemplary process steps in a method for fabricating a I II -nitride passivation layer on an AlGaN/GaN HEMT device using …
FIGS. 3A and 3B are block diagrams illustrating embodiments of a passivated AlGaN/GaN HEMT that includes a I II -nitride passivation layer formed by ALE in …
FIG. 4 B) curves of AlGaN/GaN HEMTs having a SiN X passivation layer in accordance with the p ri or art and an A l N passivation layer formed by ALE in …
FIG. 5 is a plot showing non-recoverable off-state breakdown during drain voltage sweep at a rate of 2V/sec for AlGaN/GaN HEMTs having a conventional SiN X …
FIG. 6 is a plot showing the change in dynamic R O N f o r va rious quie sc ent p o int drain voltage stress for AlGaN/GaN HEMTs having a conventional SiN X …
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 forming a passivated AlGaN/GaN HEMT, comprising: forming a GaN buffer/channel layer on a substrate; forming an AlGaN barrier layer on the GaN buffer/channel layer to form an AlGaN/GaN structure; etching mesa isolation trenches in the AlGaN barrier layer to define an area on an upper surface of the barrier layer on which a source, a drain, and a gate element of a HEMT are to be formed; subjecting the AlGaN/GaN structure to an ex situ cleaning to prepare the AlGaN/GaN structure for growth of a I II -nitride passivation layer thereon; placing the cleaned AlGaN/GaN structure into an atomic layer epitaxy (ALE) reaction chamber and subjecting the AlGaN/GaN structure to an in situ cleaning to further prepare the AlGaN/GaN structure for growth of the I II -nitride passivation layer thereon; growing the I II -nitride passivation layer on an upper surface of the AlGaN barrier layer by ALE at a temperature of about 300 ° C to about 850 ° C to form a passivated AlGaN/GaN structure; etching the I II -nitride passivation layer to expose portions of the AlGaN surface for deposition of materials for source, a gate, and a drain electrodes; and forming the source, gate, and drain electrodes on the portions of the AlGaN surface defined by the etched passivation layer.
The method according to claim 1, wherein the I II -nitride passivation layer is grown to a thickness of about 0.5 nm to about 300 nm.
The method according to claim 1, wherein the I II -nitride passivation material is A lN.
The method according to claim 1, wherein the I II -nitride passivation layer is etched in a Cl 2 plasma.
The method according to claim 1, wherein the I II -nitride passivation layer is etched in a heated AZ₄₀₀K developer.
The method according to claim 1, wherein the gate metal is a Ni/Au Schottky metal.
The method according to claim 1, wherein the gate metal is deposited by electron beam evaporation.
The method according to claim 1, wherein the gate metal is patterned by liftoff.
The method according to claim 1, further comprising depositing a layer of dielectric material on the AlGaN/GaN HEMT before growth of the I II -nitride passivation layer thereon.
The method according to claim 11, wherein the I II -nitride passivation layer comprises a relaxed I II -nitride material.
The method according to claim 11, wherein the I II -nitride passivation layer comprises a nonrelaxed I II -nitride material.
A method for forming a passivated AlGaN/GaN HEMT, comprising: forming a GaN buffer/channel layer on a substrate; forming an AlGaN barrier layer on the GaN buffer/channel layer to form an AlGaN/GaN structure; etching mesa isolation trenches in the AlGaN barrier layer to define an area on an upper surface of the barrier layer on which a source, a drain, and a gate element of a HEMT are to be formed; forming the source and drain elements on the surface of the AlGaN barrier layer; subjecting the AlGaN/GaN structure to an ex situ cleaning to prepare the AlGaN/GaN structure for growth of a I II -nitride passivation layer thereon; placing the cleaned AlGaN/GaN structure into an atomic layer epitaxy (ALE) reaction chamber and subjecting the AlGaN/GaN structure to an in situ cleaning to further prepare the AlGaN/GaN structure for growth of the I II -nitride passivation layer thereon; growing the I II -nitride passivation layer on an upper surface of the AlGaN barrier layer by ALE at a temperature of about 300 ° C to about 850 ° C to form a passivated AlGaN/GaN structure; etching the I II -nitride passivation layer to expose a portions of the AlGaN surface for deposition of a gate electrode thereon; and forming gate electrode on the portions of the AlGaN surface defined by the etched passivation layer.
The method according to claim 12, wherein the I II -nitride passivation layer comprises a relaxed I II -nitride material.
The method according to claim 12, wherein the I II -nitride passivation layer comprises a nonrelaxed I II -nitride material.
The method according to claim 12, wherein
The method according to claim 12, wherein thickness of about 0.5 nm to about 300 nm.
The method according to claim 12, further material on the AlGaN/GaN HEMT before growth Page 22 of 23 the I II -nitride passivation material is A lN. the I II -nitride passivation layer is grown to a comprising depositing a layer of dielectric of the I II -nitride passivation layer thereon.
Layer stacks claimed or described, ordered top of device to substrate.
passivated AlGaN/GaN HEMT
Materials described outside the worked examples.
III-nitride passivation layer
GaN buffer/channel layer
GaN
Additional fabrication and treatment steps described in the patent.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
Temperature | 300–850 °C | — |
Temperature |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 9,490,356Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 is a block diagram illustrating an unpassivated AlGaN/GaN HEMT in accordance with the prior art. [021]
FIG. 2 provides a flow chart outlining exemplary process steps in a method for fabricating a I II -nitride passivation layer on an AlGaN/GaN HEMT device using …
FIGS. 3A and 3B are block diagrams illustrating embodiments of a passivated AlGaN/GaN HEMT that includes a I II -nitride passivation layer formed by ALE in …
FIG. 4 B) curves of AlGaN/GaN HEMTs having a SiN X passivation layer in accordance with the p ri or art and an A l N passivation layer formed by ALE in …
FIG. 5 is a plot showing non-recoverable off-state breakdown during drain voltage sweep at a rate of 2V/sec for AlGaN/GaN HEMTs having a conventional SiN X …
FIG. 6 is a plot showing the change in dynamic R O N f o r va rious quie sc ent p o int drain voltage stress for AlGaN/GaN HEMTs having a conventional SiN X …
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 forming a passivated AlGaN/GaN HEMT, comprising: forming a GaN buffer/channel layer on a substrate; forming an AlGaN barrier layer on the GaN buffer/channel layer to form an AlGaN/GaN structure; etching mesa isolation trenches in the AlGaN barrier layer to define an area on an upper surface of the barrier layer on which a source, a drain, and a gate element of a HEMT are to be formed; subjecting the AlGaN/GaN structure to an ex situ cleaning to prepare the AlGaN/GaN structure for growth of a I II -nitride passivation layer thereon; placing the cleaned AlGaN/GaN structure into an atomic layer epitaxy (ALE) reaction chamber and subjecting the AlGaN/GaN structure to an in situ cleaning to further prepare the AlGaN/GaN structure for growth of the I II -nitride passivation layer thereon; growing the I II -nitride passivation layer on an upper surface of the AlGaN barrier layer by ALE at a temperature of about 300 ° C to about 850 ° C to form a passivated AlGaN/GaN structure; etching the I II -nitride passivation layer to expose portions of the AlGaN surface for deposition of materials for source, a gate, and a drain electrodes; and forming the source, gate, and drain electrodes on the portions of the AlGaN surface defined by the etched passivation layer.
The method according to claim 1, wherein the I II -nitride passivation layer is grown to a thickness of about 0.5 nm to about 300 nm.
The method according to claim 1, wherein the I II -nitride passivation material is A lN.
The method according to claim 1, wherein the I II -nitride passivation layer is etched in a Cl 2 plasma.
The method according to claim 1, wherein the I II -nitride passivation layer is etched in a heated AZ₄₀₀K developer.
The method according to claim 1, wherein the gate metal is a Ni/Au Schottky metal.
The method according to claim 1, wherein the gate metal is deposited by electron beam evaporation.
The method according to claim 1, wherein the gate metal is patterned by liftoff.
The method according to claim 1, further comprising depositing a layer of dielectric material on the AlGaN/GaN HEMT before growth of the I II -nitride passivation layer thereon.
The method according to claim 11, wherein the I II -nitride passivation layer comprises a relaxed I II -nitride material.
The method according to claim 11, wherein the I II -nitride passivation layer comprises a nonrelaxed I II -nitride material.
A method for forming a passivated AlGaN/GaN HEMT, comprising: forming a GaN buffer/channel layer on a substrate; forming an AlGaN barrier layer on the GaN buffer/channel layer to form an AlGaN/GaN structure; etching mesa isolation trenches in the AlGaN barrier layer to define an area on an upper surface of the barrier layer on which a source, a drain, and a gate element of a HEMT are to be formed; forming the source and drain elements on the surface of the AlGaN barrier layer; subjecting the AlGaN/GaN structure to an ex situ cleaning to prepare the AlGaN/GaN structure for growth of a I II -nitride passivation layer thereon; placing the cleaned AlGaN/GaN structure into an atomic layer epitaxy (ALE) reaction chamber and subjecting the AlGaN/GaN structure to an in situ cleaning to further prepare the AlGaN/GaN structure for growth of the I II -nitride passivation layer thereon; growing the I II -nitride passivation layer on an upper surface of the AlGaN barrier layer by ALE at a temperature of about 300 ° C to about 850 ° C to form a passivated AlGaN/GaN structure; etching the I II -nitride passivation layer to expose a portions of the AlGaN surface for deposition of a gate electrode thereon; and forming gate electrode on the portions of the AlGaN surface defined by the etched passivation layer.
The method according to claim 12, wherein the I II -nitride passivation layer comprises a relaxed I II -nitride material.
The method according to claim 12, wherein the I II -nitride passivation layer comprises a nonrelaxed I II -nitride material.
The method according to claim 12, wherein
The method according to claim 12, wherein thickness of about 0.5 nm to about 300 nm.
The method according to claim 12, further material on the AlGaN/GaN HEMT before growth Page 22 of 23 the I II -nitride passivation material is A lN. the I II -nitride passivation layer is grown to a comprising depositing a layer of dielectric of the I II -nitride passivation layer thereon.
Layer stacks claimed or described, ordered top of device to substrate.
passivated AlGaN/GaN HEMT
Materials described outside the worked examples.
III-nitride passivation layer
GaN buffer/channel layer
GaN
Additional fabrication and treatment steps described in the patent.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
Temperature | 300–850 °C | — |
Temperature |
Related documents with shared materials, methods, properties, or citations.
AlN passivation layer
AlN
Ni/Au Schottky metal
Ni/Au
dielectric material
AlGaN barrier layer
AlGaN
| 300–500 °C |
| — |
Thickness | 0.5–300 nm | — |
AlN passivation layer
AlN
Ni/Au Schottky metal
Ni/Au
dielectric material
AlGaN barrier layer
AlGaN
| 300–500 °C |
| — |
Thickness | 0.5–300 nm | — |
AlN passivation layer
AlN
Ni/Au Schottky metal
Ni/Au
dielectric material
AlGaN barrier layer
AlGaN
| 300–500 °C |
| — |
Thickness | 0.5–300 nm | — |
AlN passivation layer
AlN
Ni/Au Schottky metal
Ni/Au
dielectric material
AlGaN barrier layer
AlGaN
| 300–500 °C |
| — |
Thickness | 0.5–300 nm | — |