Patent US5767018A successfully refreshed from Google Patents.
US5767018A
Expired / Lapsed
US
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Method of etching a polysilicon pattern
Assignee: GlobalFoundries Inc
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Filing: 1995-11-08
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Granted: 1998-06-16
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Expires: 2015-11-08
Abstract
Abstract Pitting in active regions along the edges of a gate electrode when etching a composite comprising an anti-reflective coating on polysilicon is avoided by etching the anti-reflective coating with an etchant that forms a protective passivating coating on at least the sidewalls of the etched anti-reflective pattern and on the underlying polysilicon layer. Subsequently, anisotropic etching is conducted to remove the protective passivating coating from the surface of the polysilicon layer, leaving the etched anti-reflective pattern protected from the main polysilicon etch on at least its sidewalls by the passivating coating to prevent interaction. In another embodiment, the anti-reflective coating is etched without formation of a passivating coating, and the polysilicon layer subsequently etched with an etchant that forms a passivating coating.
Inventors
- 👤 Scott A. Bell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:45
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/71
Claims Analysis
Total Claims: 50
Claim 1
Independent Claim
116 words
A method of etching a composite comprising a dielectric underlayer, a polysilicon layer on the dielectric underlayer, and a dielectric coating on the polysilicon layer, which method comprises: removing portions of the dielectric coating with a first etchant to form a dielectric pattern comprising sidewalls on the polysilicon layer, whereby a passivating coating is formed on at least a sidewall of the dielectric pattern and on the polysilicon layer; anisotropically etching the passivating coating with a second etchant to expose a portion of the polysilicon layer leaving a portion of the passivating coating on at least the sidewall of the dielectric pattern; and etching the polysilicon layer with a third etchant to form a polysilicon pattern.
Claim 2
Independent Claim
116 words
A method of etching a composite comprising a dielectric underlayer, a polysilicon layer on the dielectric underlayer, and a dielectric coating on the polysilicon layer, which method comprises: removing portions of the dielectric coating with a first etchant to form a dielectric pattern comprising sidewalls on the polysilicon layer, whereby a passivating coating is formed on at least a sidewall of the dielectric pattern and on the polysilicon layer; anisotropically etching the passivating coating with a second etchant to expose a portion of the polysilicon layer leaving a portion of the passivating coating on at least the sidewall of the dielectric pattern; and etching the polysilicon layer with a third etchant to form a polysilicon pattern.
Claim 3
Dependent Claim
21 words
The method according to claim 1, further comprising overetching with a fourth etchant to remove a portion of the dielectric underlayer.
Claim 4
Dependent Claim
31 words
The method according to claim 1, wherein the dielectric coating comprises a material selected from the group consisting of a silicon oxide, silicon nitride, silicon oxynitride, titanium nitride and titanium oxynitride.
Claim 5
Dependent Claim
12 words
The method according to claim 1, wherein the first etchant comprises oxygen.
Claim 6
Dependent Claim
15 words
The method according to claim 4, wherein the first etchant further comprises a fluorinated hydrocarbon.
Claim 7
Dependent Claim
14 words
The method according to claim 5, wherein the fluorinated hydrocarbon is CHF 3 .
Claim 8
Dependent Claim
22 words
The method according to claim 1, wherein the second etchant comprises SF 6 , Cl 2 , He and O 2 .
Claim 9
Dependent Claim
16 words
The method according to claim 1, wherein the third etchant comprises HBr and Cl 2 .
Claim 10
Dependent Claim
17 words
The method according to claim 2, wherein the fourth etchant comprises HBr, He and O 2 .
Claim 11
Dependent Claim
30 words
The method according to claim 1, wherein the etched dielectric pattern is encapsulated with the passivating coating, and the dielectric pattern remains encapsulated with the passivating coating after anisotropic etching.
Claim 12
Dependent Claim
16 words
The method according to claim 1, wherein the passivating coating comprises an inorganic or organic material.
Claim 13
Dependent Claim
14 words
The method according to claim 11, wherein the passivating coating comprises an organic polymer.
Claim 14
Dependent Claim
28 words
The method according to claim 1, wherein the dielectric coating is etched in a first chamber and the subsequent etching steps are conducted in a different second chamber.
Claim 15
Dependent Claim
20 words
The method according to claim 1, wherein the passivating coating has a thickness of about 50 to about 1000 Å.
Claim 16
Dependent Claim
20 words
The method according to claim 14, wherein the passivating coating has a thickness of about 100 to about 300 Å.
Claim 17
Dependent Claim
126 words
The method according to claim 1, comprising: forming a dielectric underlayer; depositing a polysilicon layer on the dielectric underlayer; depositing a dielectric coating on the polysilicon layer; forming a resist mask pattern on the dielectric coating; removing portions of the dielectric coating with a first etchant to form a dielectric pattern comprising sidewalls on the polysilicon layer, whereby a passivating organic polymeric coating is formed encapsulating the dielectric pattern and on the polysilicon layer; anisotropically etching the passivating coating with a second etchant to expose a portion of the polysilicon layer, leaving the dielectric pattern encapsulated with the passivating coating; etching the polysilicon layer with a third etchant to form a pattern; and overetching with a fourth etchant to remove a portion of the dielectric layer.
Claim 18
Dependent Claim
38 words
The method according to claim 16, further comprising depositing the dielectric underlayer on a semiconductor substrate; depositing a dielectric anti-reflective material on the polysilicon layer; and etching the polysilicon layer to form a gate electrode of a transistor.
Claim 19
Dependent Claim
16 words
The method according to claim 16, wherein the first etchant comprises oxygen and a fluorinated hydrocarbon.
Claim 20
Dependent Claim
14 words
The method according to claim 18, wherein the fluorinated hydrocarbon is CHF 3 .
Claim 21
Dependent Claim
22 words
The method according to claim 16, wherein the second etchant comprises SF 6 , Cl 2 , He and O 2 .
Claim 22
Independent Claim
120 words
A method of manufacturing a semiconductor device, which method comprises: depositing a dielectric underlayer; depositing a layer of polysilicon on the dielectric underlayer; forming a dielectric coating on the polysilicon layer; removing a portion of the dielectric coating with a first etchant to form a dielectric pattern comprising sidewalls on the polysilicon layer, whereby a passivating polymer-containing coating is formed on at least a sidewall of the dielectric pattern and on the polysilicon layer; anisotropically etching the passivating coating with a second etchant to expose a portion of the polysilicon layer leaving a portion of the passivating coating on at least the sidewall of the dielectric pattern; and etching the polysilicon layer with a third etchant to form a pattern.
Claim 23
Independent Claim
120 words
A method of manufacturing a semiconductor device, which method comprises: depositing a dielectric underlayer; depositing a layer of polysilicon on the dielectric underlayer; forming a dielectric coating on the polysilicon layer; removing a portion of the dielectric coating with a first etchant to form a dielectric pattern comprising sidewalls on the polysilicon layer, whereby a passivating polymer-containing coating is formed on at least a sidewall of the dielectric pattern and on the polysilicon layer; anisotropically etching the passivating coating with a second etchant to expose a portion of the polysilicon layer leaving a portion of the passivating coating on at least the sidewall of the dielectric pattern; and etching the polysilicon layer with a third etchant to form a pattern.
Claim 24
Dependent Claim
21 words
The method according to claim 21, further comprising overetching to remove a portion of the dielectric underlayer with a fourth etchant.
Claim 25
Dependent Claim
69 words
The method according to claim 21, further comprising: depositing the dielectric underlayer on a semiconductor substrate; depositing a dielectric coating comprising an anti-reflective material selected from the group consisting of a silicon oxide, silicon nitride, silicon oxynitride, titanium nitride, and titanium oxynitride on the polysilicon layer; forming a resist mask pattern on the dielectric anti-reflective coating; and etching the polysilicon layer to form a gate electrode of a transistor.
Claim 26
Dependent Claim
16 words
The method according to claim 21, wherein the first etchant comprises a fluorinated hydrocarbon and oxygen.
Claim 27
Dependent Claim
14 words
The method according to claim 24, wherein the fluorinated hydrocarbon is CHF 3 .
Claim 28
Dependent Claim
22 words
The method according to claim 21, wherein the second etchant comprises SF 6 , Cl 2 , He and O 2 .
Claim 29
Dependent Claim
27 words
The method according to claim 21, wherein the passivating coating encapsulates the dielectric pattern, and the dielectric pattern remains encapsulated with the passivating coating after anisotropic etching.
Claim 30
Dependent Claim
28 words
The method according to claim 21, wherein the dielectric coating is etched in a first chamber and the subsequent etching steps are conducted in a different second chamber.
Claim 31
Dependent Claim
20 words
The method according to claim 21, wherein the passivating coating has a thickness of about 50 to about 1000 Å.
Claim 32
Dependent Claim
20 words
The method according to claim 29, wherein the passivating coating has a thickness of about 100 to about 300 Å.
Claim 33
Dependent Claim
14 words
The method according to claim 23, wherein the anti-reflective material is a silicon oxynitride.
Claim 34
Dependent Claim
20 words
The method according to claim 1, comprising etching the polysilicon layer using the etched dielectric coating as a hard mask.
Claim 35
Dependent Claim
20 words
The method according to claim 21, comprising etching the polysilicon layer using the etched dielectric coating as a hard mask.
Claim 36
Independent Claim
98 words
A method of etching a composite comprising a dielectric underlayer, a polysilicon layer on the dielectric underlayer, and a dielectric coating on the polysilicon layer, which method comprises: removing portions of the dielectric coating with a first etchant to form a dielectric pattern comprising sidewalls on the polysilicon layer, whereby a passivating coating is not formed on the dielectric pattern or the polysilicon layer; and etching the polysilicon layer with a second etchant to form a polysilicon pattern, whereby a passivating coating is formed on the sidewalls of the etched dielectric pattern while the polysilicon layer is etched.
Claim 37
Independent Claim
98 words
A method of etching a composite comprising a dielectric underlayer, a polysilicon layer on the dielectric underlayer, and a dielectric coating on the polysilicon layer, which method comprises: removing portions of the dielectric coating with a first etchant to form a dielectric pattern comprising sidewalls on the polysilicon layer, whereby a passivating coating is not formed on the dielectric pattern or the polysilicon layer; and etching the polysilicon layer with a second etchant to form a polysilicon pattern, whereby a passivating coating is formed on the sidewalls of the etched dielectric pattern while the polysilicon layer is etched.
Claim 38
Dependent Claim
21 words
The method according to claim 34, further comprising overetching with a third etchant to remove a portion of the dielectric underlayer.
Claim 39
Dependent Claim
31 words
The method according to claim 34, wherein the dielectric coating comprises a material selected from the group consisting of a silicon oxide, silicon nitride, silicon oxynitride, titanium nitride and titanium oxynitride.
Claim 40
Dependent Claim
14 words
The method according to claim 34, wherein the first etchant comprises SF 6 .
Claim 41
Dependent Claim
20 words
The method according to claim 37, wherein the first etchant further comprises Cl 2 , He and O 2 .
Claim 42
Dependent Claim
16 words
The method according to claim 34, wherein the second etchant comprises He and O 2 .
Claim 43
Dependent Claim
17 words
The method according to claim 39, wherein the second etchant further comprises HBr and Cl 2 .
Claim 44
Dependent Claim
16 words
The method according to claim 34, wherein the passivating coating comprises an inorganic or organic material.
Claim 45
Dependent Claim
14 words
The method according to claim 41, wherein the passivating coating comprises an organic polymer.
Claim 46
Dependent Claim
20 words
The method according to claim 42, wherein the passivating coating has a thickness of about 50 to about 1000 Å.
Claim 47
Dependent Claim
20 words
The method according to claim 43, wherein the passivating coating has a thickness of about 100 to about 300 Å.
Claim 48
Dependent Claim
38 words
The method according to claim 34, further comprising: depositing the dielectric underlayer on a semiconductor substrate; depositing a dielectric anti-reflective coating on the polysilicon layer; and etching the polysilicon layer to form a gate electrode of a transistor.
Claim 49
Dependent Claim
20 words
The method according to claim 34, comprising etching the polysilicon layer using the etched dielectric coating as a hard mask.
Claim 50
Dependent Claim
18 words
The method according to claim 34, comprising etching the dielectric coating and polysilicon layer in the same chamber.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-06-15 | 2001-12-15 | 2002-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-06-15 | 2005-12-15 | 2006-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-06-15 | 2009-12-15 | 2010-06-16 | $7700.00 | Window Closed / Lapsed |