US7598108B2
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Gallium nitride-on-silicon interface using multiple aluminum compound buffer layers
Assignee: Sharp Corp
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Filing: 2007-07-06
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Granted: 2009-10-06
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Expires: 2027-07-06
Abstract
Abstract A thermal expansion interface between silicon (Si) and gallium nitride (GaN) films using multiple buffer layers of aluminum compounds has been provided, along with an associated fabrication method. The method provides a ( 111 ) Si substrate and deposits a first layer of AlN overlying the substrate by heating the substrate to a relatively high temperature of 1000 to 1200° C. A second layer of AlN is deposited overlying the first layer of AlN at a lower temperature of 500 to 800° C. A third layer of AlN is deposited overlying the second layer of AlN by heating the substrate to the higher temperature range. Then, a grading Al 1-X Ga X N layer is formed overlying the third layer of AlN, where 0<X<1, followed by a fixed composition Al 1-X Ga X N layer overlying the first grading Al 1-X Ga X N layer. An epitaxial GaN layer can then be grown overlying the fixed composition Al 1-X Ga X N layer.
Inventors
- 👤 Tingkai Li
- 👤 Douglas J. Tweet
- 👤 Jer-shen Maa
- 👤 Sheng Teng Hsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:22
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/80; H10D62/81; H10D62/815; H10D62/8161; H10D62/8162; H10D62/8164; H10D62/82; H10D62/824; H10D62/85; H10D62/8503; H10P; H10P14/00; H10P14/20; H10P14/24; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/32; H10P14/3202; H10P14/3214; H10P14/3216; H10P14/3242; H10P14/3244; H10P14/3251; H10P14/3254; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3416; H10P14/27; H10P14/276
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
184 words
A method for forming a thermal expansion interface between silicon (Si) and gallium nitride (GaN) films using multiple buffer layers of aluminum compounds, the method comprising: providing a ( 111 ) Si substrate; depositing a first layer of AIN overlying the substrate, heating the substrate to a temperature within a first range; depositing a second layer of AlN directly overlying and in contact with the first layer of AlN, hearing the substrate to a temperature within a second range, lower than the first range; depositing a third layer of AlN directly overlying and in contact with the second layer of AlN, heating the substrate to a temperature within the first range; forming a first grading Al 1-X Ga X N layer directly overlying and in contact with the third layer of AlN, where 0<X<1; forming a first fixed composition Al 1-X Ga X N layer directly overlying and in contact with the first grading Al 1-X Ga X N layer, where 0<X<1; and, growing a first epitaxial GaN layer directly overlying and in contact with the fixed composition Al 1-X Ga X N layer.
Claim 2
Independent Claim
184 words
A method for forming a thermal expansion interface between silicon (Si) and gallium nitride (GaN) films using multiple buffer layers of aluminum compounds, the method comprising: providing a ( 111 ) Si substrate; depositing a first layer of AIN overlying the substrate, heating the substrate to a temperature within a first range; depositing a second layer of AlN directly overlying and in contact with the first layer of AlN, hearing the substrate to a temperature within a second range, lower than the first range; depositing a third layer of AlN directly overlying and in contact with the second layer of AlN, heating the substrate to a temperature within the first range; forming a first grading Al 1-X Ga X N layer directly overlying and in contact with the third layer of AlN, where 0<X<1; forming a first fixed composition Al 1-X Ga X N layer directly overlying and in contact with the first grading Al 1-X Ga X N layer, where 0<X<1; and, growing a first epitaxial GaN layer directly overlying and in contact with the fixed composition Al 1-X Ga X N layer.
Claim 3
Dependent Claim
28 words
The method of claim 1 wherein depositing the first and third AlN layers includes depositing AlN at a temperature within a first range of 1000 to 1200° C.
Claim 4
Dependent Claim
37 words
The method of claim 2 wherein forming the first grading and first fixed composition Al 1-X Ga X N layers includes depositing each Al 1-X Ga X N layer at a substrate temperature within the first range.
Claim 5
Dependent Claim
25 words
The method of claim 2 wherein growing the first epitaxial GaN layer includes depositing the GaN layer at a substrate temperature within the first range.
Claim 6
Dependent Claim
26 words
The method of claim 1 wherein depositing the second AlN layer includes depositing AlN at a temperature within a second range of 500 to 800° C.
Claim 7
Dependent Claim
43 words
The method of claim 1 wherein depositing the first, second, and third AlN layers includes introducing Al (III) and N (IV) precursors in a chemical vapor deposition (CVD) process having a III to IV mole ratio in a range of 500 to 4000.
Claim 8
Dependent Claim
30 words
The method of claim 1 wherein depositing the first and second AlN layers includes depositing each AlN layer to a thickness in a range of 10 to 50 nanometers (nm).
Claim 9
Dependent Claim
25 words
The method of claim 1 wherein depositing the third AlN layer includes depositing AlN to a thickness in a range of 100 to 500 nm.
Claim 10
Dependent Claim
40 words
The method of claim 1 wherein forming the first grading and first fixed composition Al 1-X Ga X N layers includes forming each Al 1-X Ga X N layer having a thickness in a range of 10 to 500 nm.
Claim 11
Dependent Claim
58 words
The method of claim 1 wherein forming the first grading and first fixed composition Al 1-X Ga X N layers includes forming each Al 1-X Ga X N layer by introducing Ga (III) and Al (III), and N (IV) precursors in a CVD process having a III to IV mole ratio in a range of 500 to 4000.
Claim 12
Dependent Claim
28 words
The method of claim 1 wherein growing the first epitaxial GaN layer includes forming a GaN layer having a thickness in a range of 500 to 3000 nm.
Claim 13
Dependent Claim
43 words
The method of claim 1 wherein growing the first epitaxial GaN layer includes forming a GaN layer by introducing Ga (III) and N (IV) precursors in a CVD process having a III to IV mole ratio in a range of 500 to 4000.
Claim 14
Dependent Claim
69 words
The method of claim 1 further comprising: subsequent to growing the first epitaxial GaN layer, forming a second grading Al 1-X Ga X N layer overlying the first epitaxial GaN layer, forming a second fixed composition Al 1-X Ga X N layer overlying the second grading Al 1-X Ga X N layer, and growing a second epitaxial GaN layer overlying the fixed composition Al 1-X Ga X N layer.
Claim 15
Dependent Claim
46 words
The method of claim 13 further comprising: forming a patterned layer overlying the second epitaxial GaN layer, selected from a group consisting of anodized aluminum oxide (AAO) and block polymer; and, using a lateral nanoheteroepitaxy overgrowth (LNEO) process, growing a GaN layer overlying the patterned layer.
Claim 16
Dependent Claim
39 words
The method of claim 14 wherein forming the patterned layer of AAO includes using a film material selected from a group consisting of AlN, an AlN/grading AlGaN (Al 1-x Ga x N (0<X<1)) stack, an AlN/AlGaN/GaN stack, and Al.
Claim 17
Dependent Claim
62 words
The method of claim 14 wherein forming the patterned layer includes forming a layer having a thickness in a range of 10 to 500 nm, and pattern openings having a diameter in a range between 5 and 100 nm, a depth extending through the patterned layer thickness, and a distance between openings in a range between 100 nm and 2 micrometers (μm).
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