US4894349A
Expired / Lapsed
US
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Two step vapor-phase epitaxial growth process for control of autodoping
Assignee: Toshiba Corp
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Filing: 1988-12-15
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Granted: 1990-01-16
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Expires: 2008-12-15
Abstract
Abstract A process for forming a vapor-phase epitaxial growth layer on a silicon wafer having a buried layer of a high As or B concentration. This vapor-phase epitaxial growth process is performed in two steps of (i) performing a vapor-phase epitaxial growth at a relatively low temperature by using a reaction gas containing at least one kind selected from a group consisting of SiH x F 4-x (x=0 to 3) and Si 2 H x F 6-x (x=0-5) and at least one kind selected from a group consisting of SiH 4 and Si 2 H 6 , and (ii) performing a vapor-phase epitaxial growth under a condition which allows a higher growth rate that in the step (i) by using a reaction gas containing SiH 4 or Si 2 H 6 which may or may not be accompanied with silane fluoride.
Inventors
- 👤 Yoshihiko Saito
- 👤 Yoshiaki Matsushita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:48
CPC Classifications
H; H10; H10W; H10W15/00; H10P; H10P14/00; H10P14/20; H10P14/24; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/2921; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/3438; H10P14/3441; H10P14/3442; H10P14/3444; H10P32/00; H10P32/10; H10P32/15; H10W15/01; Y; Y10; Y10S; Y10S148/00; Y10S148/007; Y10S148/025; Y10S148/169
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
192 words
A vapor-phase epitaxial growth process comprising: (i) a step of performing a vapor-phase epitaxial growth at a temperature of 600° C. to 900° C. by using a reaction gas prepared by mixing at least one kind selected from a group consisting of SiH x F 4-x (x=0 to 3) and Si 2 H x F 6-x (x=0-5), and at least one kind selected from a group consisting of SiH 4 and Si 2 H 6 thereby to form a first epitaxial layer on a silicon wafer having a high impurity concentration buried layer containing arsenic (As) or boron (B) as a dopant; and (ii) a step of performing a vapor-phase epitaxial growth at a growth rate higher than that performed in step (i) by using a reaction gas a group consisting of SiH 4 and Si 2 H 6 , or a reaction gas containing at least one kind of the silane and at least one kind of silane fluoride selected from a group consisting of SiH x F 4-x (x=0 to 3) and Si 2 H x F 6-x (x=0-5), thereby forming a second epitaxial layer on said first epitaxial layer.
Claim 2
Dependent Claim
192 words
A vapor-phase epitaxial growth process comprising: (i) a step of performing a vapor-phase epitaxial growth at a temperature of 600° C. to 900° C. by using a reaction gas prepared by mixing at least one kind selected from a group consisting of SiH x F 4-x (x=0 to 3) and Si 2 H x F 6-x (x=0-5), and at least one kind selected from a group consisting of SiH 4 and Si 2 H 6 thereby to form a first epitaxial layer on a silicon wafer having a high impurity concentration buried layer containing arsenic (As) or boron (B) as a dopant; and (ii) a step of performing a vapor-phase epitaxial growth at a growth rate higher than that performed in step (i) by using a reaction gas a group consisting of SiH 4 and Si 2 H 6 , or a reaction gas containing at least one kind of the silane and at least one kind of silane fluoride selected from a group consisting of SiH x F 4-x (x=0 to 3) and Si 2 H x F 6-x (x=0-5), thereby forming a second epitaxial layer on said first epitaxial layer.
Claim 3
Dependent Claim
24 words
A vapor-phase epitaxial growth process according to claim 1, wherein the step (i) is performed at a temperature of 600° C. to 800° C.
Claim 4
Dependent Claim
24 words
A vapor-phase epitaxial growth process according to claim 1, wherein the step (i) is performed while the temperature of the silicon wafer is rising.
Claim 5
Dependent Claim
19 words
A vapor-phase epitaxial growth process according to claim 1, wherein the step (i) is performed at a fixed temperature.
Claim 6
Dependent Claim
23 words
A vapor-phase epitaxial growth process according to claim 1, wherein the step (i) is performed under a pressure of 100 torr or below.
Claim 7
Dependent Claim
27 words
A vapor-phase epitaxial growth process according to claim 1, wherein the first epitaxial layer formed in the step (i) has a thickness of 0.3 μm or less.
Claim 8
Dependent Claim
27 words
A vapor-phase epitaxial growth process according to claim 1, wherein the first epitaxial layer formed in the step (i) has a thickness of 0.05 μm or less.
Claim 9
Dependent Claim
29 words
A vapor-phase epitaxial growth process according to claim 1, wherein the second epitaxial layer is formed in the step (ii) at a growth rate of 0.05 μm/min. or above.
Claim 10
Dependent Claim
31 words
A vapor-phase epitaxial growth process according to claim 1, wherein the mixture ratio of the silane fluoride and the silane in the reaction gas used in the step (i) is 5-30:1.
Claim 11
Dependent Claim
34 words
A vapor-phase epitaxial growth process according to claim 1, wherein said silicon wafer is of a twin tub structure consisting of a high boron concentration buried layer and a high arsenic concentration buried layer.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-01-15 | 1993-07-17 | 1994-01-16 | $2000.00 | Window Closed / Lapsed |
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