US4855249A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for growing III-V compound semiconductors on sapphire using a buffer layer
Assignee: Nagoya University
•
Filing: 1988-03-16
•
Granted: 1989-08-08
•
Expires: 2008-03-16
Abstract
Abstract In organometallic vapor phase hetero-epitaxial processes for growing AlxGal-xN films on a sapphire substrate, the substrate is subjected to a preheat treatment of brief duration, such as less than 2 minutes, at relatively low temperatures in an atmosphere comprising Al-containing organometallic compound, NH3 and H2 l gases, prior to the hetero epitaxial growth of AlxGal-xN films. Thus, single crystalline AlxGal-xN layers of high uniformity and high quality having smooth, flat surfaces are provided. Multi-layers grown according to the process of the invention are free from cracks and have preferable UV or blue light emission properties.
Inventors
- 👤 Isamu Akasaki
- 👤 Nobuhiko Sawaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:40
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/01; H10H20/011; H10H20/013; H10H20/0133; H10H20/01335; H10H20/052; H10P; H10P14/00; H10P14/20; H10P14/24; H10P14/29; H10P14/2901; H10P14/2921; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3416; H10P14/36; H10P14/3602; Y; Y10; Y10S; Y10S117/00; Y10S117/913; Y10S148/00; Y10S148/025; Y10S148/072; Y10S148/097; Y10S148/11; Y10S148/113; Y10S438/00; Y10S438/967
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
135 words
A process for growing a compound semiconductor wherein an organometallic compound and ammonia gas (NH3) are reacted in hydrogen gas (H 2 ) or hydrogen gas mixed with nitrogen gas (N 2 ) to grow epitaxially at least one layer of single crystalline Al x Ga 1-x N (0≦x<1) on a sapphire substrate, said process comprising subjecting the sapphire substrate to a heat treatment of brief duration in a atmosphere comprising at least an Al-containing organometallic compound, NH 3 , and H 2 at a temperature lower than the single crystalline AlN growing temperature to deposit a non-single crystalline buffer layer of an AlN compound on the surface of the sapphire substrate and thereafter growing epitaxially at a high temperature said single crystalline Al x Ga 1-x N directly on said non-single crystalline buffer layer.
Claim 2
Dependent Claim
135 words
A process for growing a compound semiconductor wherein an organometallic compound and ammonia gas (NH3) are reacted in hydrogen gas (H 2 ) or hydrogen gas mixed with nitrogen gas (N 2 ) to grow epitaxially at least one layer of single crystalline Al x Ga 1-x N (0≦x<1) on a sapphire substrate, said process comprising subjecting the sapphire substrate to a heat treatment of brief duration in a atmosphere comprising at least an Al-containing organometallic compound, NH 3 , and H 2 at a temperature lower than the single crystalline AlN growing temperature to deposit a non-single crystalline buffer layer of an AlN compound on the surface of the sapphire substrate and thereafter growing epitaxially at a high temperature said single crystalline Al x Ga 1-x N directly on said non-single crystalline buffer layer.
Claim 3
Dependent Claim
28 words
A process as claimed in claim 1, wherein the temperature in the heat treatment of the sapphire substrate is in the range between 800° C. and 1,100° C.
Claim 4
Dependent Claim
17 words
A process as claimed in claim 2, wherein said temperature is from 900° C. to 1,000° C.
Claim 5
Dependent Claim
30 words
A process as claimed in claim 1, wherein the temperature for the epitaxial growth of Al x Ga 1-x N is in the range between 950° C. and 1,150° C.
Claim 6
Dependent Claim
17 words
A process as claimed in claim 4, wherein said temperature is from 970° C. to 1,030° C.
Claim 7
Dependent Claim
25 words
A process as claimed in claim 1, wherein the subscript x of the formula, Al x Ga 1-x N, is form 0 to 0.3 inclusive.
Claim 8
Dependent Claim
18 words
A process as claimed in claim 1, wherein the duration of heat treatment is less than 2 minutes.
Claim 9
Dependent Claim
18 words
A process as claimed in claim 7, wherein said duration of heat treatment is not exceeding 1 minute.
Claim 10
Dependent Claim
14 words
A process as claimed in claim 1, wherein said Al-containing organometallic compound is trimethyl-aluninum.
References Cited (Backward Citations)
US3922475A
Cited
US4177321A
Cited
US4144116A
Cited
US4062706A
Cited
US4147571A
Cited
US4120706A
Cited
US4554030A
Cited
US4561916A
Cited
US4614961A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-08-07 | 1993-02-06 | 1993-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-07 | 1997-02-06 | 1997-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-07 | 2001-02-06 | 2001-08-08 | $7700.00 | Window Closed / Lapsed |