US4717446A
Expired / Lapsed
US
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Method of detecting the endpoint of the etch of epitaxially grown silicon
Assignee: Motorola Solutions Inc
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Filing: 1986-09-18
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Granted: 1988-01-05
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Expires: 2006-09-18
Abstract
Abstract A method of detecting the endpoint of expitaxially grown silicon using a monitor wafer is described. A monitor wafer having a substrate, an oxide layer, and a polysilicon layer is process in an epi chamber along with working wafers. The monitor wafer is used to determine the endpoint of the working wafers epi layer when the epi layer is etched.
Inventors
- 👤 Andrew G. Nagy
- 👤 Donald K. Stemple
- 👤 Clarence J. Tracy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:12
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/005; B24B37/013; G; G01; G01B; G01B11/00; G01B11/02; G01B11/06; G01B11/0616; G01B11/0683; H; H10; H10P; H10P74/00; H10P74/23; H10P74/238
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
96 words
A method of detecting the endpoint of epitaxially grown silicon comprising the steps of: providing a working wafer having a silicon substrate; providing a monitor wafer having a substrate, an oxide layer disposed on said substrate, and a polysilicon layer disposed on said oxide layer; growing an epitaxial layer on said working wafer and said monitor wafer simultaneously; etching said working wafer and said monitor wafer; detecting an endpoint between said polysilicon layer and said oxide layer of said monitor wafer using a laser; and halting said etching when said endpoint is detected by said laser.
Claim 2
Independent Claim
96 words
A method of detecting the endpoint of epitaxially grown silicon comprising the steps of: providing a working wafer having a silicon substrate; providing a monitor wafer having a substrate, an oxide layer disposed on said substrate, and a polysilicon layer disposed on said oxide layer; growing an epitaxial layer on said working wafer and said monitor wafer simultaneously; etching said working wafer and said monitor wafer; detecting an endpoint between said polysilicon layer and said oxide layer of said monitor wafer using a laser; and halting said etching when said endpoint is detected by said laser.
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein said epitaxial layer grown on said working wafer is an epitaxial silicon layer.
Claim 4
Dependent Claim
19 words
The method of claim 1 wherein said epitaxial layer grown on said monitor wafer is an epitaxial polysilicon layer.
Claim 5
Dependent Claim
14 words
The method of claim 1 wherein said step of etching is a dry etching.
Claim 6
Dependent Claim
13 words
The method of claim 4 wherein said dry etching is a plasma etching.
Claim 7
Dependent Claim
17 words
The method of claim 1 wherein said step of detecting said endpoint is performed by laser interferometry.
Claim 8
Independent Claim
100 words
A method of detecting the endpoint of epitaxially grown silicon comprising the steps of: providing a working wafer having a silicon substrate; providing a monitor wafer having a substrate, an oxide layer disposed on said substrate, and a polysilicon layer disposed on said oxide layer; growing an epitaxial layer on said working wafer and said monitor wafer simultaneously; processing said working wafer; etching said working wafer and said monitor wafer; detecting an endpoint between said polysilicon layer and said oxide layer of said monitor wafer using a laser; and halting said etching when said endpoint is detected by said laser.
Claim 9
Independent Claim
100 words
A method of detecting the endpoint of epitaxially grown silicon comprising the steps of: providing a working wafer having a silicon substrate; providing a monitor wafer having a substrate, an oxide layer disposed on said substrate, and a polysilicon layer disposed on said oxide layer; growing an epitaxial layer on said working wafer and said monitor wafer simultaneously; processing said working wafer; etching said working wafer and said monitor wafer; detecting an endpoint between said polysilicon layer and said oxide layer of said monitor wafer using a laser; and halting said etching when said endpoint is detected by said laser.
Claim 10
Dependent Claim
19 words
The method of claim 7 wherein said epitaxial layer grown on said working wafer is an epitaxial silicon layer.
Claim 11
Dependent Claim
19 words
The method of claim 7 wherein said epitaxial layer grown on said monitor wafer is an epitaxial polysilicon layer.
Claim 12
Dependent Claim
14 words
The method of claim 7 wherein said step of etching is a dry etching.
Claim 13
Dependent Claim
13 words
The method of claim 10 wherein said dry etching is a plasma etching.
Claim 14
Dependent Claim
17 words
The method of claim 7 wherein said step of detecting said endpoint is performed by laser interferometry.
Claim 15
Independent Claim
112 words
A method of detecting the endpoint of epitaxially grown silicon comprising the steps of: providing a working wafer having a silicon substrate; providing a monitor wafer having a substrate, an oxide layer disposed on said substrate, and a polysilicon layer disposed on said oxide layer; growing an epitaxial layer of silicon on said working wafer and an epitaxial layer of polysilicon on said monitor wafer simultaneously; processing said working wafer; etching said working wafer and said monitor wafer using a plasma etcher; detecting an endpoint between said polysilicon layer and said oxide layer of said monitor wafer using laser interferometry; and halting said etching when said endpoint is detected by said laser.
Claim 16
Independent Claim
112 words
A method of detecting the endpoint of epitaxially grown silicon comprising the steps of: providing a working wafer having a silicon substrate; providing a monitor wafer having a substrate, an oxide layer disposed on said substrate, and a polysilicon layer disposed on said oxide layer; growing an epitaxial layer of silicon on said working wafer and an epitaxial layer of polysilicon on said monitor wafer simultaneously; processing said working wafer; etching said working wafer and said monitor wafer using a plasma etcher; detecting an endpoint between said polysilicon layer and said oxide layer of said monitor wafer using laser interferometry; and halting said etching when said endpoint is detected by said laser.
References Cited (Backward Citations)
US4367044A
Cited
US4435898A
Cited
USPTO Annuity & Maintenance Windows
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| 3.5 Years (Year 4) | 1991-01-04 | 1991-07-06 | 1992-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-04 | 1995-07-06 | 1996-01-05 | $3760.00 | Window Closed / Lapsed |
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