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US5069747A
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US
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Creation and removal of temporary silicon dioxide structures on an in-process integrated circuit with minimal effect on exposed, permanent silicon dioxide structures
Assignee: Micron Technology Inc
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Filing: 1990-12-21
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Granted: 1991-12-03
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Expires: 2010-12-21
Abstract
Abstract A process for creating and removing temporary silicon dioxide structures on an in-process integrated circuit with minimal effect on existing permanent silicon dioxide structures that are exposed. The process comprises the steps of blanket depositing an ozone-TEOS silicon dioxide layer through chemical vapor deposition on top of the in-process integrated circuit, thus covering permanent structures formed from conventional silicon dioxides (e.g. TEOS and thermal oxides), etching the ozone-TEOS layer to create said temporary structures, and removing the temporary structures using dilute hydrofluoric acid.
Inventors
- 👤 David A. Cathey
- 👤 Mark E. Tuttle
- 👤 Ruojia Lee
- 👤 Tyler A. Lowrey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:13
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D30/0227; H10D64/00; H10D64/01; H10D64/021; H10P; H10P30/00; H10P30/20; H10P30/22; H10P76/00; H10P76/40; H10P76/408; H10P76/4085; H10P14/00; H10P14/60; H10P14/63; H10P14/6326; H10P14/6328; H10P14/6334; H10P14/6336; H10P14/6339; H10P14/69; H10P14/692; H10P14/6921; H10P14/69215
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
84 words
A process for creating and removing temporary silicon dioxide structures on an in-process integrated circuit with minimal effect on existing permanent structures formed from conventional silicon dioxides that are exposed, said process comprising the following sequence of steps: a) blanket deposition of an ozone-TEOS silicon dioxide layer through chemical vapor deposition on top of the in-process integrated circuit, thus covering the permanent structures formed from conventional silicon dioxides; b) etching said ozone-TEOS layer to create said temporary structures; and c) removing said temporary structures.
Claim 2
Dependent Claim
84 words
A process for creating and removing temporary silicon dioxide structures on an in-process integrated circuit with minimal effect on existing permanent structures formed from conventional silicon dioxides that are exposed, said process comprising the following sequence of steps: a) blanket deposition of an ozone-TEOS silicon dioxide layer through chemical vapor deposition on top of the in-process integrated circuit, thus covering the permanent structures formed from conventional silicon dioxides; b) etching said ozone-TEOS layer to create said temporary structures; and c) removing said temporary structures.
Claim 3
Dependent Claim
41 words
The process of claim 1, wherein chemical vapor deposition of said ozone-TEOS layer is accomplished by introducing a feed stream containing oxygen gas, ozone gas, and tetraethyl-orthosilicate gas into a deposition chamber, where the gases are heated to approximately 400° C.
Claim 4
Dependent Claim
16 words
The process of claim 2, wherein said temporary structures are created using an anisotropic plasma etch.
Claim 5
Dependent Claim
15 words
The process of claim 3, wherein said temporary structures are removed with dilute hydrofluoric acid.
Claim 6
Dependent Claim
21 words
The process of claim 3, wherein said dilute hydrofluoric acid has a concentration between approximately 4:1 to approximately 1000:1 by volume.
Claim 7
Dependent Claim
45 words
The process of claim 1, wherein sidewall implant spacers comprised of both a permanent structure portion and a temporary structure portion are utilized to offset source/drain implants from the edges of conductive strips, which overlie a silicon substrate, and from which FET gates are formed.
Claim 8
Dependent Claim
32 words
The process of claim 1, wherein sidewall implant spacers comprised of both a permanent structure portion and a temporary structure portion are utilized to offset source/drain implants from the edges of wordlines.
Claim 9
Dependent Claim
26 words
The process of claim 7, wherein said temporary structure portion is removed from said sidewall implant spacers in order to increase the space between adjacent wordlines.
Claim 10
Dependent Claim
24 words
The process of claim 8, wherein additional space between adjacent wordlines is required for adequate connection of a buried contact layer to the substrate.
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) | 1994-12-02 | 1995-06-03 | 1995-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-02 | 1999-06-03 | 1999-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-02 | 2003-06-03 | 2003-12-03 | $7700.00 | Window Closed / Lapsed |