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US6624452B2
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Gallium nitride-based HFET and a method for fabricating a gallium nitride-based HFET
Assignee: University of California
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Filing: 2001-07-30
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Granted: 2003-09-23
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Expires: 2021-07-30
Abstract
Abstract A GaN-based HFET includes a set of layers all having a common face polarity, i.e., all being either Ga-face or N-face. One of the layers is a thin barrier layer having a first face with a positive charge and a second face with a negative charge thereby causing a potential change to occur between the two faces. The if potential change causes the barrier layer to prevent electron flow from a channel layer into a buffer layer. The GaN-based HFET may also be fabricated without a top barrier layer to obtain an inverted GaN-based HFET.
Inventors
- 👤 Edward T. Yu
- 👤 Peter M. Asbeck
- 👤 Silvanus S. Lau
- 👤 Xiaozhong Dang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:25
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/051; H10D30/015; H10D30/40; H10D30/47; H10D30/471; H10D30/473; H10D30/4732; H10D30/80; H10D30/801; H10D62/00; H10D62/80; H10D62/85; H10D62/8503
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
107 words
A GaN-based HFET comprising: a buffer layer; a channel layer; a bottom barrier layer disposed between the buffer layer and the channel layer, the bottom barrier layer being less than 500 Å thick and having a first face with a positive charge and having a second face with a negative charge such that a potential change occurs between the first and second faces thereby forming an electron barrier between the channel layer and the buffer layer; a top barrier layer disposed on the channel layer; and wherein the buffer layer, the bottom barrier layer, the channel layer and the top barrier layer have a common face polarity.
Claim 2
Dependent Claim
107 words
A GaN-based HFET comprising: a buffer layer; a channel layer; a bottom barrier layer disposed between the buffer layer and the channel layer, the bottom barrier layer being less than 500 Å thick and having a first face with a positive charge and having a second face with a negative charge such that a potential change occurs between the first and second faces thereby forming an electron barrier between the channel layer and the buffer layer; a top barrier layer disposed on the channel layer; and wherein the buffer layer, the bottom barrier layer, the channel layer and the top barrier layer have a common face polarity.
Claim 3
Dependent Claim
13 words
The GaN-based HFET of claim 1 wherein the common face polarity is Ga-face.
Claim 4
Dependent Claim
13 words
The GaN-based HFET of claim 1 wherein the common face polarity is N-face.
Claim 5
Dependent Claim
48 words
The GaN-based HFET of claim 1 wherein the buffer layer comprises Gallium Nitride, wherein the bottom barrier layer comprises Indium Gallium Nitride, wherein the channel layer comprises Gallium Nitride, and wherein the top barrier layer comprises Aluminum Gallium Nitride, and further wherein the common face polarity is Ga-face.
Claim 6
Dependent Claim
35 words
The GaN-based HFET of claim 1 wherein the top barrier layer comprises a representative Aluminum mol fraction of twenty percent, and wherein the bottom barrier layer comprises a representative Indium mol fraction of eight percent.
Claim 7
Dependent Claim
49 words
The GaN-based HFET of claim 1 wherein the buffer layer comprises Aluminum Gallium Nitride, wherein the bottom barrier layer comprises Gallium Nitride, wherein the channel layer comprises Aluminum Gallium Nitride, and wherein the top barrier layer comprises Aluminum Gallium Nitride, and further wherein the common face polarity is Ga-face.
Claim 8
Dependent Claim
26 words
The GaN-based HFET of claim 6 wherein the buffer layer and channel layer comprise a representative Aluminum mol fraction ranging from five percent to ten percent.
Claim 9
Dependent Claim
50 words
The GaN-based HFET of claim 6 wherein the top barrier layer comprises a representative Aluminum mol fraction of twenty four percent, and wherein the channel layer comprises a representative Aluminum mol fraction of eight percent and further wherein the buffer layer comprises a representative Aluminum mol fraction of eight percent.
Claim 10
Dependent Claim
47 words
The GaN-based HFET of claim 6 wherein the top barrier layer comprises a representative Aluminum mol fraction of eight percent; wherein the channel layer comprises a representative Aluminum mol fraction of eight percent, and wherein the buffer layer comprises a representative Aluminum mol fraction of eight percent.
Claim 11
Dependent Claim
34 words
The GaN-based HFET of claim 6 wherein the buffer layer further comprises GaN that grades into AlGaN and further wherein the buffer layer is doped with a dopant to compensate for buffer layer leakage.
Claim 12
Dependent Claim
11 words
The GaN-based HFET of claim 10 wherein the dopant comprises Be.
Claim 13
Dependent Claim
47 words
The GaN-based HFET of claim 1 wherein the buffer layer comprises Gallium Nitride, wherein the bottom barrier layer comprises Aluminum Gallium Nitride, wherein the channel layer comprises Gallium Nitride and wherein the top barrier layer comprises Indium Gallium Nitride and further wherein the face polarity is N-face.
Claim 14
Dependent Claim
17 words
The GaN-based HFET of claim 1 wherein the bottom barrier layer is less than 100 Å thick.
Claim 15
Dependent Claim
29 words
The GaN-based HFET of claim 1 , wherein the bottom barrier layer is selected from one of InGaN and GaN having a thickness in the range of 75-100 Å.
Claim 16
Dependent Claim
92 words
An inverted GaN-based HFET comprising: a buffer layer; a channel layer; a barrier layer disposed between the buffer layer and the channel layer, the barrier layer being less than 500 Å thick and having a first face with a positive charge and having a second face with a negative charge such that a potential change occurs between the first and second faces thereby forming an electron barrier between the channel layer and the buffer layer; and, wherein the buffer layer, the barrier layer, and the channel layer have a common face polarity.
Claim 17
Dependent Claim
92 words
An inverted GaN-based HFET comprising: a buffer layer; a channel layer; a barrier layer disposed between the buffer layer and the channel layer, the barrier layer being less than 500 Å thick and having a first face with a positive charge and having a second face with a negative charge such that a potential change occurs between the first and second faces thereby forming an electron barrier between the channel layer and the buffer layer; and, wherein the buffer layer, the barrier layer, and the channel layer have a common face polarity.
Claim 18
Dependent Claim
29 words
The GaN-based HFET of claim 15 , wherein the bottom barrier layer is selected from one of InGaN and GaN having a thickness in the range of 75-100 Å.
Claim 19
Dependent Claim
15 words
The inverted GaN-based HFET of claim 15 wherein the common face polarity is Ga-face polarity.
Claim 20
Dependent Claim
15 words
The inverted GaN-based HFET of claim 15 wherein the common face polarity is N-face polarity.
Claim 21
Dependent Claim
43 words
The inverted GaN-based HFET of claim 15 wherein the buffer layer comprises GaN, wherein the barrier layer comprises InGaN, and wherein the channel layer comprises GaN, and further wherein the buffer layer, the barrier layer and the channel layer have a Ga-face polarity.
Claim 22
Dependent Claim
26 words
The inverted GaN-based HFET of claim 15 wherein the channel layer is doped with Silicon causing a concentration of electrons to form in the channel layer.
Claim 23
Dependent Claim
30 words
The inverted GaN-based HFET of claim 15 wherein the buffer layer and the barrier layer are doped with Silicon causing a concentration of electrons to form in the channel layer.
Claim 24
Dependent Claim
48 words
The inverted GaN-based HFET of claim 15 wherein the buffer layer comprises Aluminum Gallium Nitride, wherein the barrier layer comprises Gallium Nitride, and wherein the channel layer comprises Aluminum Gallium Nitride, and further wherein the buffer layer, the barrier layer and the channel layer have a Ga-face polarity.
Claim 25
Dependent Claim
47 words
The inverted GaN-based HFET of claim 15 wherein the buffer layer comprises Gallium Nitride, wherein the barrier layer comprises Aluminum Gallium Nitride, and wherein the channel layer comprises Gallium Nitride, and further wherein the buffer layer, the barrier layer and the channel layer have an N-face polarity.
References Cited (Backward Citations)
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