EP0365875A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Capped anneal
Assignee: Texas Instruments Inc
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Filing: 1989-10-03
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Granted: —
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Expires: 2009-10-03
Abstract
Abstract Heteroepitaxy of lattice-mismatched semiconductor materials such as GaAs on silicon is accomplished by first growing GaAs (104) on silicon (102), then growing a lattice matched cap of Al x Ga 1- x As (106), next annealing out defects with the Al x Ga 1- x As cap (106) limiting desorption of gallium, lastly growing further GaAs (110) directly on the cap. The lattice matched cap is also used as an implant anneal cap.
Inventors
- 👤 Yung-Chung Kao
- 👤 Donald L. Plumton
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 17:28
CPC Classifications
H; H10; H10P; H10P95/00; H10P95/90; H10P95/904; H10P14/00; H10P14/20; H10P14/22; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/32; H10P14/3202; H10P14/3214; H10P14/3221; H10P14/3242; H10P14/3244; H10P14/3251; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3421; H10P14/38; Y; Y10; Y10S; Y10S148/00; Y10S148/003; Y10S148/065; Y10S438/00; Y10S438/902; Y10S438/933
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
78 words
A method of forming a heteroepitaxial structure, comprising the steps of: (a) forming a heteroepitaxial layer of a second material on a layer of a first material; (b) forming a capping layer on said heteroepitaxial layer, said capping layer substantially lattice matched to said second material; (c) annealing said said heteroepitaxial and capping layers; and (d) forming a top layer of a third material on said capping layer, said third material substantially lattice matched to said capping layer.
Claim 2
Independent Claim
78 words
A method of forming a heteroepitaxial structure, comprising the steps of: (a) forming a heteroepitaxial layer of a second material on a layer of a first material; (b) forming a capping layer on said heteroepitaxial layer, said capping layer substantially lattice matched to said second material; (c) annealing said said heteroepitaxial and capping layers; and (d) forming a top layer of a third material on said capping layer, said third material substantially lattice matched to said capping layer.
Claim 3
Dependent Claim
41 words
The method of claim 1, wherein: (a) said first material is silicon; (b) said second and third materials are both GaAs; and (c) said capping layer is made of Al x Ga 1- x As for 0 < x ≦ 1.0.
Claim 4
Dependent Claim
18 words
The method of claim 2, wherein: (a) said annealing is in an arsenic atmosphere at about 850 C.
Claim 5
Dependent Claim
22 words
The method of claim 1, wherein: (a) said formings are by molecular beam epitaxial growth and said annealing is in situ .
Claim 6
Dependent Claim
13 words
The method of claim 1, wherein: (a) said capping layer is a superlattice.
Claim 7
Dependent Claim
14 words
The method of claim 5, wherein: (a) said superlattice is grown with temperature cycling.
Claim 8
Dependent Claim
32 words
The method of claim 1, wherein: (a) said heteroepitaxial layer is formed by growth at a first temperature followed by growth at a second temperature which is higher than said first temperature.
Claim 9
Independent Claim
37 words
A method of annealing a semiconductor layer, comprising the steps of: (a) forming a substantially lattice matched cap on a semiconductor layer; (b) heating said semiconductor layer plus cap; and (c) removing said cap after said heating.
Claim 10
Independent Claim
37 words
A method of annealing a semiconductor layer, comprising the steps of: (a) forming a substantially lattice matched cap on a semiconductor layer; (b) heating said semiconductor layer plus cap; and (c) removing said cap after said heating.
Claim 11
Dependent Claim
24 words
The method of claim 8, further comprising the step of: (a) implanting dopants through said cap into said semiconductor layer prior to said heating.
Claim 12
Dependent Claim
29 words
The method of claim 9, wherein: (a) said semiconductor layer is GaAs; and (b) said cap is Al x Ga 1- x As for 0 < x ≦ 1.0.
Claim 13
Dependent Claim
27 words
The method of claim 9, wherein: (a) said semiconductor layer is GaAs; and (b) said cap is Al x Ga 1- x As for x = 0.5.
Claim 14
Dependent Claim
43 words
The method of claim 8, wherein: (a) said semiconductor layer is GaAs; (b) said cap is Al x Ga 1- x As for 0 < x ≦ 1.0; (c) said forming is by epitaxial growth; and (d) said heating is rapid thermal annealing.
Claim 15
Dependent Claim
73 words
An integrated circuit, comprising: (a) a compound substrate including a bottom layer of silicon, a heteroepitaxial buffer layer on said silicon, a cap layer substantially lattice matched to and on said buffer layer, and a device layer substantially lattice matched to and on said cap layer, said cap layer made of material less volatile than the material of said buffer layer; (b) devices in said device layer; and (c) interconnections among said devices.
Claim 16
Dependent Claim
73 words
An integrated circuit, comprising: (a) a compound substrate including a bottom layer of silicon, a heteroepitaxial buffer layer on said silicon, a cap layer substantially lattice matched to and on said buffer layer, and a device layer substantially lattice matched to and on said cap layer, said cap layer made of material less volatile than the material of said buffer layer; (b) devices in said device layer; and (c) interconnections among said devices.
Claim 17
Dependent Claim
38 words
The integrated circuit of claim 13, wherein: (a) said cap layer is made of Al x Ga 1- x As for 0 < x ≦ 1.0; and (b) said buffer and device layers are both made of GaAs.
Claim 18
Dependent Claim
83 words
A semiconductor device, comprising: (a) a layer of a first compound semiconductor; (b) at least one doped region at the surface and in said layer; (c) a metal contact on said at least one doped region, the interface between said metal contact and said doped region characterized by an anneal of said doped region with a cap made of a second compound semiconductor prior to formation of said metal contact, said second compound semiconductor related to but different from said first compound semiconductor.
Claim 19
Dependent Claim
83 words
A semiconductor device, comprising: (a) a layer of a first compound semiconductor; (b) at least one doped region at the surface and in said layer; (c) a metal contact on said at least one doped region, the interface between said metal contact and said doped region characterized by an anneal of said doped region with a cap made of a second compound semiconductor prior to formation of said metal contact, said second compound semiconductor related to but different from said first compound semiconductor.
Claim 20
Dependent Claim
36 words
The device of claim 15, wherein: (a) said layer is made of Al x Ga 1- x As; and (b) said cap is made of Al y Ga 1- y As with y > x .
References Cited (Backward Citations)
No citation records indexed.
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