US6649287B2
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Gallium nitride materials and methods
Assignee: MACOM Technology Solutions Holdings Inc
•
Filing: 2000-12-14
•
Granted: 2003-11-18
•
Expires: 2020-12-14
Abstract
Abstract The invention provides semiconductor materials including a gallium nitride material layer formed on a silicon substrate and methods to form the semiconductor materials. The semiconductor materials include a transition layer formed between the silicon substrate and the gallium nitride material layer. The transition layer is compositionally-graded to lower stresses in the gallium nitride material layer which can result from differences in thermal expansion rates between the gallium nitride material and the substrate. The lowering of stresses in the gallium nitride material layer reduces the tendency of cracks to form. Thus, the invention enables the production of semiconductor materials including gallium nitride material layers having few or no cracks. The semiconductor materials may be used in a number of microelectronic and optical applications.
Inventors
- 👤 T. Warren Weeks, Jr.
- 👤 Edwin L. Piner
- 👤 Thomas Gehrke
- 👤 Kevin J. Linthicum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:25
CPC Classifications
C; C30; C30B; C30B23/00; C30B23/02; H; H10; H10D; H10D62/00; H10D62/80; H10D62/81; H10D62/815; H10D62/8161; H10D62/8162; H10D62/8164; C30B23/025; C30B25/00; C30B25/02; C30B25/18; C30B25/183; C30B29/00; C30B29/02; C30B29/06; C30B29/10; C30B29/40; C30B29/403; C30B29/406; C30B29/60; C30B29/68; H10D30/00; H10D30/01; H10D30/015; H10D30/40; H10D30/47; H10D30/471; H10D30/475; H10D30/4755; H10D30/60; H10D62/10; H10D62/113; H10D62/115; H10D62/40; H10D62/405; H10D62/82; H10D62/824; H10D62/826; H10D62/85; H10D62/852; H10H; H10H20/00; H10H20/01; H10H20/011; H10H20/013; H10H20/0133; H10H20/01335; H10H20/0137; H10H20/80; H10H20/81; H10H20/811; H10H20/812; H10H20/815; H10H20/822; H10H20/824; H10H20/825; H10P; H10P14/00; H10P14/20; H10P14/24; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/2922; H10P14/2924; H10P14/2925; H10P14/2926; H10P14/32; H10P14/3202; H10P14/3204; H10P14/3211; H10P14/3214; H10P14/3216; H10P14/3242; H10P14/3244; H10P14/3251; H10P14/3252; H10P14/3254; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3416; H10P14/3451; H10P14/3452; H10P14/3458; H10D62/8503; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 72
Claim 1
Independent Claim
35 words
A semiconductor material comprising: a silicon substrate; a compositionally-graded transition layer formed directly on the silicon substrate; and a gallium nitride material layer formed over the transition layer, wherein the semiconductor material forms a FET.
Claim 2
Dependent Claim
35 words
A semiconductor material comprising: a silicon substrate; a compositionally-graded transition layer formed directly on the silicon substrate; and a gallium nitride material layer formed over the transition layer, wherein the semiconductor material forms a FET.
Claim 3
Dependent Claim
23 words
The semiconductor material of claim 1 , wherein the composition of the transition layer is graded discontinuously across the thickness of the layer.
Claim 4
Dependent Claim
45 words
The semiconductor material of claim 1 , wherein the transition layer comprises an alloy of gallium nitride selected from the group consisting of Al x In y Ga (1-x-y) N, In y Ga (1-y) N, and Al x Ga (1-x) N, wherein 0≦x≦1 and 0≦y≦1.
Claim 5
Dependent Claim
18 words
The semiconductor material of claim 3 , wherein the concentration of gallium in the transition layer is graded.
Claim 6
Dependent Claim
50 words
The semiconductor material of claim 3 , wherein x and/or y is varied from a first value at a back surface of the transition layer to a second value at a front surface of the transition layer, wherein the back surface is closer to the substrate than the front surface.
Claim 7
Dependent Claim
28 words
The semiconductor material of claim 5 , wherein the sum of the value of x and the value of y at the back surface is greater than 0.4.
Claim 8
Dependent Claim
28 words
The semiconductor material of claim 5 , wherein the sum of the value of x and the value of y at the back surface is greater than 0.8.
Claim 9
Dependent Claim
33 words
The semiconductor material of claim 5 , wherein the transition layer comprises Al x Ga (1-x) N at the back surface of the transition layer in contact with the silicon substrate, wherein 0≦x≦1.
Claim 10
Dependent Claim
28 words
The semiconductor material of claim 5 , wherein the sum of the value of x and the value of y at the front surface is less than 0.3.
Claim 11
Dependent Claim
47 words
The semiconductor material of claim 5 , wherein the transition layer comprises GaN at a front surface of the transition layer in contact with the gallium nitride material layer and is free of gallium at a back surface of the transition layer in contact with the substrate.
Claim 12
Dependent Claim
18 words
The semiconductor material of claim 3 , wherein the transition layer comprises Al x Ga (1-x) N, 0≦x≦1.
Claim 13
Dependent Claim
21 words
The semiconductor material of claim 3 , wherein the value of x decreases in a direction away from the silicon substrate.
Claim 14
Dependent Claim
18 words
The semiconductor material of claim 3 , wherein the value of v remains constant across the transition layer.
Claim 15
Dependent Claim
14 words
The semiconductor material of claim 1 , wherein the transition layer comprises a superlattice.
Claim 16
Dependent Claim
36 words
The semiconductor material of claim 14 , wherein the superlattice includes a series of alternating Al x In y Ga (1-x-y) N and Al a In b Ga (1-a-b) N layers, wherein 0≦x≦1, 0≦y≦1, 0≦a≦1, 0≦b≦1.
Claim 17
Dependent Claim
35 words
The semiconductor material of claim 15 , wherein the of value of x, y, a, and b are constant across respective layers and the thickness of the respective layers is varied across the transition layer.
Claim 18
Dependent Claim
22 words
The semiconductor material of claim 1 , wherein the transition layer has a thickness between about 0.03 micron and about 20 microns.
Claim 19
Dependent Claim
15 words
The semiconductor material of claim 1 , wherein the gallium nitride material layer comprises GaN.
Claim 20
Dependent Claim
25 words
The semiconductor material of claim 1 , wherein the gallium nitride material layer comprises Al x In y Ga (1-x-y) N, wherein 0≦x≦1 and 0≦y≦1.
Claim 21
Dependent Claim
21 words
The semiconductor material of claim 1 , wherein the gallium nitride material layer has a thickness of greater than 0.75 micron.
Claim 22
Dependent Claim
24 words
The semiconductor material of claim 1 , wherein the gallium nitride material layer has a crack level of less than 0.005 μm/μm 2 .
Claim 23
Dependent Claim
24 words
The semiconductor material of claim 1 , wherein the gallium nitride material layer has a crack level of less than 0.001 μm/μm 2 .
Claim 24
Dependent Claim
18 words
The semiconductor material of claim 1 , wherein the gallium nitride material layer is substantially free of cracks.
Claim 25
Dependent Claim
15 words
The semiconductor material of claim 1 , wherein the gallium nitride material layer is monocrystalline.
Claim 26
Dependent Claim
19 words
The semiconductor material of claim 1 , wherein the silicon substrate has a thickness of greater than 250 micron.
Claim 27
Dependent Claim
13 words
The semiconductor material of claim 1 , wherein the silicon substrate is textured.
Claim 28
Dependent Claim
17 words
The semiconductor material of claim 1 , further comprising an intermediate layer formed over the transition layer.
Claim 29
Dependent Claim
38 words
The semiconductor material of claim 27 , wherein the intermediate layer comprises an alloy of gallium nitride selected from the group consisting of Al x In y Ga (1-x-y) In y Ga (1-y) N, wherein 0≦x≦1 and 0≦y≦1.
Claim 30
Dependent Claim
15 words
The semiconductor material of claim 1 , wherein the silicon substrate comprises a silicon wafer.
Claim 31
Independent Claim
41 words
A method of producing a PET comprising: forming a compositionally-graded transition layer directly on a silicon substrate; forming a gallium nitride material layer over the transition layer to produce a semiconductor structure; and processing the semiconductor structure to form a PET.
Claim 32
Independent Claim
41 words
A method of producing a PET comprising: forming a compositionally-graded transition layer directly on a silicon substrate; forming a gallium nitride material layer over the transition layer to produce a semiconductor structure; and processing the semiconductor structure to form a PET.
Claim 33
Dependent Claim
44 words
The method of claim 30 , wherein the transition layer comprises an alloy of gallium nitride selected from the group consisting of Al x In y Ga (1-x-y) N, In y Ga (1-y) N, and Al x Ga (1-x) N, wherein 0≦x≦1 and 0≦y≦1.
Claim 34
Dependent Claim
17 words
The method of claim 30 , wherein the concentration of gallium in the transition layer is graded.
Claim 35
Dependent Claim
20 words
The method of claim 31 , wherein the value of x decreases in a direction away from the silicon substrate.
Claim 36
Dependent Claim
18 words
The method of claim 31 , wherein the transition layer comprises Al x Ga (1-x) N, wherein 0≦x≦1.
Claim 37
Dependent Claim
39 words
The method of claim 30 , wherein the transition layer comprises a superlattice including a series of alternating Al x In y Ga (1-x-y) N, Al a In b Ga (1-a-b) N layers, wherein 0≦x≦1, 0≦y≦1, 0≦a≦1, 0≦b ≦1.
Claim 38
Dependent Claim
14 words
The method of claim 30 , wherein the gallium nitride material layer comprises GaN.
Claim 39
Dependent Claim
38 words
The method of claim 30 , wherein the gallium nitride material layer comprises Al x In y Ga (1-x-y) N, wherein x and y are greater than or equal to 0 and less than or equal to 1.
Claim 40
Dependent Claim
23 words
The method of claim 30 , wherein the gallium nitride material layer has a crack level of less than 0.005 μm/μm 2 .
Claim 41
Dependent Claim
23 words
The method of claim 30 , wherein the gallium nitride material layer has a crack level of less than 0.001 μm/μm 2 .
Claim 42
Dependent Claim
17 words
The method of claim 30 , wherein the gallium nitride material layer is substantially free of cracks.
Claim 43
Dependent Claim
14 words
The method of claim 30 , wherein the gallium nitride material layer is monocrystalline.
Claim 44
Dependent Claim
16 words
The method of claim 30 , further comprising forming an intermediate layer over the transition layer.
Claim 45
Dependent Claim
20 words
The structure of claim 1 , wherein the gallium nitride material layer is formed directly on the compositionally-graded transition layer.
Claim 46
Dependent Claim
35 words
The structure of claim 1 , wherein the gallium nitride material layer includes an intrinsic gallium nitride layer and an Al x Ga (1-x) N layer formed on the intrinsic gallium nitride layer, wherein 0≦x≦1.
Claim 47
Dependent Claim
20 words
The structure of claim 44 , wherein the Al x Ga (1-x) N layer comprises 10-40 percent aluminum by weight.
Claim 48
Dependent Claim
14 words
The structure of claim 1 , wherein the silicon substrate is a (100) substrate.
Claim 49
Dependent Claim
16 words
The semiconductor material of claim 1 , wherein the transition layer comprises a gallium nitride alloy.
Claim 50
Dependent Claim
24 words
The semiconductor material of claim 1 , wherein the composition of the transition layer is graded across the entire thickness of the transition layer.
Claim 51
Dependent Claim
27 words
The semiconductor material of claim 1 , wherein the composition of the transition layer is graded only across a portion of the thickness of the transition layer.
Claim 52
Dependent Claim
30 words
The semiconductor material of claim 1 , further comprising an intermediate layer comprising aluminum nitride, an aluminum nitride alloy, or a gallium nitride alloy formed directly on the transition layer.
Claim 53
Dependent Claim
20 words
The semiconductor material of claim 50 , wherein the gallium nitride material layer is formed directly on the intermediate layer.
Claim 54
Dependent Claim
19 words
The semiconductor material of claim 50 , further comprising a second intermediate layer formed over the first intermediate layer.
Claim 55
Dependent Claim
21 words
The semiconductor material of claim 52 , wherein the gallium nitride material layer is formed directly on the second intermediate layer.
Claim 56
Dependent Claim
16 words
The semiconductor material of claim 28 , wherein the sum of x+y is greater than 0.8.
Claim 57
Dependent Claim
14 words
The semiconductor material of claim 27 , wherein the intermediate layer comprises aluminum nitride.
Claim 58
Dependent Claim
21 words
The semiconductor material of claim 27 , wherein the intermediate layer has a thickness between about 0.01 micron and 2.0 microns.
Claim 59
Dependent Claim
15 words
The semiconductor material of claim 27 , wherein the silicon substrate is a (100) substrate.
Claim 60
Dependent Claim
15 words
The method of claim 1 , wherein the transition layer comprises a gallium nitride alloy.
Claim 61
Dependent Claim
23 words
The method of claim 30 , wherein the composition of the transition layer is graded across the entire thickness of the transition layer.
Claim 62
Dependent Claim
26 words
The method of claim 30 , wherein the composition of the transition layer is graded only across a portion of the thickness of the transition layer.
Claim 63
Dependent Claim
29 words
The method of claim 30 , further comprising forming an intermediate layer comprising aluminum nitride, an aluminum nitride alloy, or a gallium nitride alloy directly on the transition layer.
Claim 64
Dependent Claim
19 words
The method of claim 30 , wherein the gallium nitride material layer is formed directly on the intermediate layer.
Claim 65
Dependent Claim
18 words
The method of claim 62 , further comprising forming a second intermediate layer over the first intermediate layer.
Claim 66
Dependent Claim
20 words
The method of claim 63 , wherein the gallium nitride material layer is formed directly on the second intermediate layer.
Claim 67
Dependent Claim
19 words
The method of claim 30 , wherein the gallium nitride material layer is formed directly on the transition layer.
Claim 68
Dependent Claim
13 words
The method of claim 61 , wherein the intermediate layer comprises aluminum nitride.
Claim 69
Dependent Claim
20 words
The method of claim 61 , wherein the intermediate layer has a thickness between about 0.01 micron and 2.0 microns.
Claim 70
Dependent Claim
35 words
The method of claim 30 , wherein the gallium nitride material layer includes an intrinsic gallium nitride layer and an Al x Ga (1-x) N fryer formed on the intrinsic gallium nitride layer, wherein 0≦x≦1.
Claim 71
Dependent Claim
14 words
The method of claim 30 , wherein the silicon substrate is a (100) substrate.
Claim 72
Dependent Claim
19 words
The method of claim 30 , the Al x Ga (1-x) N layer comprises 10-40 percent aluminum by weight.
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