US3847686A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming silicon epitaxial layers
Assignee: General Electric Co
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Filing: 1973-02-15
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Granted: 1974-11-12
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Expires: 1993-02-15
Abstract
Abstract This invention relates to a method of forming a silicon epitaxial layer on the surface of a body of silicon material including regions of modified conductivity type without significantly distorting or displacing the prearranged boundaries of these regions. This is accomplished by preconditioning the surface of the silicon body in the presence of hydrogen at a temperature not exceeding 1,000* C for between 5 to 30 minutes. Immediately following this preconditioning, a first silicon epitaxial layer is deposited on the preconditioned surface while maintaining the silicon body at a temperature not exceeding 1,000* C. Subsequently, a second silicon epitaxial layer is deposited over the first silicon epitaxial layer while maintaining the silicon body at a temperature not exceeding 1,250* C.
Inventors
- 👤 L Stein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:19
CPC Classifications
H; H10; H10W; H10W15/00; H10P; H10P14/00; H10P14/20; H10P14/24; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P32/00; H10P32/10; H10P32/15; H10P95/00; H10W15/01; Y; Y10; Y10S; Y10S148/00; Y10S148/007; Y10S148/037; Y10S148/085; Y10S438/00; Y10S438/914; Y10S438/916
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
106 words
AN IMPROVED METHOD OF FORMING A SILICON EPITAXIAL LAYER ON ONE MAJOR SURFACE OF A SILICON SEMICONDUCTOR BODY INCLUDING A MODIFIED CONDUCTIVITY REGION HAVING PREARRANGED BOUNDARIES, WITHOUT SIGNIFICANTLY DISTURBING THE LOCATION OF SAID BOUNDARIES, COMPRISING PRECONDITIONING SAID SURFACE TO RECIEVE SAID EPITAXIAL LAYER BY HEATING THE SILICON BODY IN HYDROGEN TO A TEMPERATUR NOT EXCEEDING 1,000*C. FOR BETWEEN 5 TO 30 MINUTES TO REMOVE EXTRANEOUS MATTER THEREFROM, AND IMMEDIATELY FOLLOWING SUCH A PRECONDITIONING DEPOSITING FROM A SILICON SOURCE SELECTED FROM THE GROUP OF SILICON TETRACHLORIDE AND SILANE AN EPITAXIAL LAYER OF SILICON ON SAID SURFACE WHILE MAINTAINING SAID SEMICONDUCTOR BODY AT A TEMPERATURE NOT EXCEEDING 1,000*C.
Claim 2
Dependent Claim
106 words
AN IMPROVED METHOD OF FORMING A SILICON EPITAXIAL LAYER ON ONE MAJOR SURFACE OF A SILICON SEMICONDUCTOR BODY INCLUDING A MODIFIED CONDUCTIVITY REGION HAVING PREARRANGED BOUNDARIES, WITHOUT SIGNIFICANTLY DISTURBING THE LOCATION OF SAID BOUNDARIES, COMPRISING PRECONDITIONING SAID SURFACE TO RECIEVE SAID EPITAXIAL LAYER BY HEATING THE SILICON BODY IN HYDROGEN TO A TEMPERATUR NOT EXCEEDING 1,000*C. FOR BETWEEN 5 TO 30 MINUTES TO REMOVE EXTRANEOUS MATTER THEREFROM, AND IMMEDIATELY FOLLOWING SUCH A PRECONDITIONING DEPOSITING FROM A SILICON SOURCE SELECTED FROM THE GROUP OF SILICON TETRACHLORIDE AND SILANE AN EPITAXIAL LAYER OF SILICON ON SAID SURFACE WHILE MAINTAINING SAID SEMICONDUCTOR BODY AT A TEMPERATURE NOT EXCEEDING 1,000*C.
Claim 3
Dependent Claim
71 words
An improved method of forming an epitaxial layer of silicon as defined in claim 1, an additional step of increasing the temperature during the epitaxial deposition of the silicon layer, after some predetermined initial thickness of silicon has been deposited on the one major face at 1,000*C or less, to a temperature in the range of between 1,100* and 1,250*C and complete the formation of the epitaxial layer at this temperature.
Claim 4
Dependent Claim
104 words
An improved method of providing a silicon epitaxial layer on a silicon body, while substantially reducing the lateral diffusion across the surface of a semiconductor body of dopant impurities from modified conductivity type regions formed in the semiconductor body, comprising preconditioning said surface to receive said epitaxial layer by heating the silicon body in hydrogen to a temperature not exceeding 1,000*C for between 5 to 30 minutes to remove extraneous matter therefrom, and immediately following such preconditioning depositing from a silicon source of silicon tetrachloride an epitaxial layer of silicon on said surface while maintaining said semiconductor body at a temperature not exceeding 1,000*C.
Claim 5
Dependent Claim
104 words
An improved method of providing a silicon epitaxial layer on a silicon body, while substantially reducing the lateral diffusion across the surface of a semiconductor body of dopant impurities from modified conductivity type regions formed in the semiconductor body, comprising preconditioning said surface to receive said epitaxial layer by heating the silicon body in hydrogen to a temperature not exceeding 1,000*C for between 5 to 30 minutes to remove extraneous matter therefrom, and immediately following such preconditioning depositing from a silicon source of silicon tetrachloride an epitaxial layer of silicon on said surface while maintaining said semiconductor body at a temperature not exceeding 1,000*C.
Claim 6
Dependent Claim
71 words
An improved method of forming an epitaxial layer of silicon as defined in claim 3, an additional step of increasing the temperature during the epitaxial deposition of the silicon layer, after some predetermined initial thickness of silicon has been deposited on the one major face at 1,000*C or less, to a temperature in the range of between 1,100* and 1,250*C and complete the formation of the epitaxial layer at this temperature.
Claim 7
Dependent Claim
35 words
The method of claim 1 in which silicon is deposited from said source to a thickness to seal adequately the dopant impurities in said modified conductivity region within the bulk of the resultant semiconductor body.
Claim 8
Dependent Claim
19 words
The method of claim 1 in which the thickness of said epitaxial layer is between 0.5 and 2 microns.
Claim 9
Dependent Claim
22 words
The method of claim 1 in which said modified conductivity region is of P-type conductivity in which the dopant impurity is boron.
Claim 10
Dependent Claim
35 words
The method of claim 3 in which silicon is deposited from said source to a thickness to seal adequately the dopant impurities in said modified conductivity region within the bulk of the resultant semiconductor body.
Claim 11
Dependent Claim
19 words
The method of claim 3 in which the thickness of said epitaxial layer is between 0.5 and 2 microns.
Claim 12
Dependent Claim
22 words
The method of claim 3 in which said modified conductivity region is of P-type conductivity in which the dopant impurity is boron.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |