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US5455069A
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Method of improving layer uniformity in a CVD reactor
Assignee: Motorola Solutions Inc
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Filing: 1992-06-01
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Granted: 1995-10-03
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Expires: 2012-06-01
Abstract
Abstract A CVD reactor with a flat generally rectangularly shaped susceptor having a leading edge including a curve which is concave in the direction of gas flow through the reactor. The reactor produces epitaxial layers on semiconductor wafers in which the uniformity of the layer is dependent upon the radius of the concave curvature.
Inventors
- 👤 Hsing-Chung Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:18
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/44; C23C16/458; C23C16/4582; C23C16/4583; C23C16/4584; C23C16/455; C23C16/45587; C23C16/45591; C30; C30B; C30B25/00; C30B25/02; C30B25/12; C30B25/14
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
181 words
A method of improving layer uniformity in a CVD reactor comprising the steps of: providing a CVD reactor having a cavity with a substantially flat surface having a wafer receiving, rotatable platform mounted on the flat surface and a gas inlet to one side of the platform and a gas outlet to an opposite side of the platform for causing gas introduced into the cavity through the gas inlet to flow across a portion of the surface and the platform; providing a substantially flat susceptor positioned on the flat surface of the cavity and substantially surrounding the rotatable platform, the susceptor having a leading edge extending from one side of a line through the gas inlet, the rotatable platform and the gas outlet to a side of the line opposite the one side; forming the leading edge of the susceptor with a generally concave curvature relative to the gas inlet; positioning a flat wafer in parallel overlying relationship on the rotatable platform; rotating the platform continuously; and introducing a vapor deposition gas into the cavity by way of the gas inlet.
Claim 2
Independent Claim
181 words
A method of improving layer uniformity in a CVD reactor comprising the steps of: providing a CVD reactor having a cavity with a substantially flat surface having a wafer receiving, rotatable platform mounted on the flat surface and a gas inlet to one side of the platform and a gas outlet to an opposite side of the platform for causing gas introduced into the cavity through the gas inlet to flow across a portion of the surface and the platform; providing a substantially flat susceptor positioned on the flat surface of the cavity and substantially surrounding the rotatable platform, the susceptor having a leading edge extending from one side of a line through the gas inlet, the rotatable platform and the gas outlet to a side of the line opposite the one side; forming the leading edge of the susceptor with a generally concave curvature relative to the gas inlet; positioning a flat wafer in parallel overlying relationship on the rotatable platform; rotating the platform continuously; and introducing a vapor deposition gas into the cavity by way of the gas inlet.
Claim 3
Dependent Claim
22 words
A method as claimed in claim 1 wherein the step of providing a susceptor includes providing a susceptor formed substantially of graphite.
Claim 4
Dependent Claim
20 words
A method as claimed in claim 1 wherein the step of positioning a flat wafer includes positioning a semiconductor wafer.
Claim 5
Dependent Claim
25 words
A method as claimed in claim 3 wherein the step of positioning a flat wafer includes positioning a wafer up to 8 inches in diameter.
Claim 6
Dependent Claim
19 words
A method as claimed in claim 3 wherein the step of providing a reactor includes providing an epitaxial reactor.
Claim 7
Dependent Claim
30 words
A method as claimed in claim 5 wherein the step of positioning a semiconductor wafer includes positioning a semiconductor wafer from one of III-V group, II-VI group, Si and Si-Ge.
Claim 8
Dependent Claim
30 words
A method as claimed in claim 3 wherein the step of forming the leading edge of the susceptor includes forming the concave curvature to provide a uniformity below approximately 0.2%.
Claim 9
Dependent Claim
39 words
A method as claimed in claim 7 wherein the step of forming the leading edge of the susceptor with a concave curvature includes forming the leading edge with a curve having a radius in the range of 8-15 cm.
Claim 10
Dependent Claim
55 words
A method as claimed in claim 7 wherein the step of forming the leading edge of the susceptor with a generally concave curvature includes forming the shape and curvature of the leading edge in accordance with a lateral gas velocity profile upstream of the susceptor leading edge so as to provide a desired layer uniformity.
Claim 11
Dependent Claim
25 words
A method as claimed in claim 3 wherein the step of providing a substantially flat susceptor includes providing a susceptor which is generally rectangularly shaped.
Claim 12
Independent Claim
189 words
A method of forming a substantially uniform epitaxial layer on a semiconductor wafer comprising the steps of: providing a CVD reactor having a cavity with a substantially flat surface having a wafer receiving, rotatable platform mounted on the flat surface and a gas inlet to one side of the platform and a gas outlet to an opposite side of the platform for causing gas introduced into the cavity through the gas inlet to flow across a portion of the surface and the platform; providing a substantially flat susceptor positioned on the flat surface of the cavity and substantially surrounding the rotatable platform, the susceptor having a leading edge extending from one side of a line through the gas inlet, the rotatable platform and the gas outlet to a side of the line opposite the one side; forming the leading edge of the susceptor with a generally concave curvature relative to the gas inlet; positioning a semiconductor wafer in parallel overlying relationship on the rotatable platform; rotating the platform continuously; and introducing a vapor deposition gas into the cavity by way of the gas inlet to form an epitaxial layer.
Claim 13
Independent Claim
189 words
A method of forming a substantially uniform epitaxial layer on a semiconductor wafer comprising the steps of: providing a CVD reactor having a cavity with a substantially flat surface having a wafer receiving, rotatable platform mounted on the flat surface and a gas inlet to one side of the platform and a gas outlet to an opposite side of the platform for causing gas introduced into the cavity through the gas inlet to flow across a portion of the surface and the platform; providing a substantially flat susceptor positioned on the flat surface of the cavity and substantially surrounding the rotatable platform, the susceptor having a leading edge extending from one side of a line through the gas inlet, the rotatable platform and the gas outlet to a side of the line opposite the one side; forming the leading edge of the susceptor with a generally concave curvature relative to the gas inlet; positioning a semiconductor wafer in parallel overlying relationship on the rotatable platform; rotating the platform continuously; and introducing a vapor deposition gas into the cavity by way of the gas inlet to form an epitaxial layer.
Claim 14
Dependent Claim
27 words
A method as claimed in claim 11 wherein the concave curvature of the leading edge of the susceptor is formed to provide a uniformity below approximately 0.2%.
Claim 15
Dependent Claim
29 words
A method as claimed in claim 12 wherein concave curvature of the leading edge of the susceptor has a curve with a radius in the range of 8-15 cm.
Claim 16
Dependent Claim
55 words
A method as claimed in claim 11 wherein the step of forming the leading edge of the susceptor with a generally concave curvature includes forming the shape and curvature of the leading edge in accordance with a lateral gas velocity profile upstream of the susceptor leading edge so as to provide a desired layer uniformity.
Claim 17
Dependent Claim
16 words
A method as claimed in claim 11 wherein the substantially flat susceptor is generally rectangular shaped.
Claim 18
Dependent Claim
25 words
A method as claimed in claim 11 wherein the step of positioning a flat wafer includes positioning a wafer up to 8 inches in diameter.
References Cited (Backward Citations)
US5077875A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-10-02 | 1999-04-03 | 1999-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-02 | 2003-04-03 | 2003-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-02 | 2007-04-03 | 2007-10-03 | $7700.00 | Window Closed / Lapsed |