US5940732A
Expired / Lapsed
US
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Method of fabricating semiconductor device
Assignee: Semiconductor Energy Laboratory Co Ltd
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Filing: 1996-11-25
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Granted: 1999-08-17
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Expires: 2016-11-25
Abstract
Abstract Method of fabricating thin-film transistors in which contact with connecting electrodes becomes reliable. When contact holes are formed, the bottom insulating layer is subjected to a wet etching process, thus producing undercuttings inside the contact holes. In order to remove the undercuttings, a light etching process is carried out to widen the contact holes. Thus, tapering section are obtained, and the covering of connection wiring is improved.
Inventors
- 👤 Hongyong Zhang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:15
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/031; H10D30/0312; H10D30/0314; H10D30/0321; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/081; H10W20/082
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
148 words
A method for fabricating a semiconductor device comprising the steps of: forming a semiconductor film on an insulating surface, said semiconductor film having at least channel, source and drain regions therein; forming a first insulating film on said semiconductor film; forming a second insulating film on said first insulating film, said second insulating film comprising a different material from said first insulating film; forming a first opening in said second insulating film by etching to expose a portion of said first insulating film in said first opening; forming a second opening in said first insulating film in order to expose a portion of said semiconductor film by etching the portion of said first insulating film exposed in said first opening using a liquid etchant whereby a portion of said second insulating film projects over said second opening; removing the projecting portion of said second insulating film by etching.
Claim 2
Independent Claim
148 words
A method for fabricating a semiconductor device comprising the steps of: forming a semiconductor film on an insulating surface, said semiconductor film having at least channel, source and drain regions therein; forming a first insulating film on said semiconductor film; forming a second insulating film on said first insulating film, said second insulating film comprising a different material from said first insulating film; forming a first opening in said second insulating film by etching to expose a portion of said first insulating film in said first opening; forming a second opening in said first insulating film in order to expose a portion of said semiconductor film by etching the portion of said first insulating film exposed in said first opening using a liquid etchant whereby a portion of said second insulating film projects over said second opening; removing the projecting portion of said second insulating film by etching.
Claim 3
Dependent Claim
14 words
The method according to claim 1, wherein said first insulating film comprises silicon oxide.
Claim 4
Dependent Claim
25 words
The method according to claim 1, wherein said second insulating film comprises a material selected from the group consisting of silicon nitride and organic resin.
Claim 5
Dependent Claim
25 words
The method according to claim 1, wherein said second insulating film comprises at least two laminated layers including an upper layer and a lower layer.
Claim 6
Dependent Claim
27 words
The method according to claim 4, wherein said first opening has tapered configuration and said upper layer has a higher degree of tapering than said lower layer.
Claim 7
Dependent Claim
14 words
The method according to claim 1, wherein said liquid etchant comprises buffered hydrofluoric acid.
Claim 8
Dependent Claim
27 words
The method according to claim 1, wherein the etching of said projecting portion is conducted by dry etching with an etching gas comprising carbon tetrafluoride and oxygen.
Claim 9
Independent Claim
152 words
A method for fabricating a semiconductor device comprising the steps of: forming a semiconductor film on an insulating surface, said semiconductor film having at least channel, source and drain regions therein; forming a first insulating film on said semiconductor film; forming an interlayer insulating film over said semiconductor film and said first insulating film, said interlayer insulating film comprising a different material from said first insulating film; forming a first opening in said interlayer insulating film by etching to expose a portion of said first insulating film in said first opening; forming a second opening in said first insulating film in order to expose a portion of said semiconductor film by etching the portion of said first insulating film exposed in said first opening using a liquid etchant whereby a portion of said interlayer insulating film projects over said second opening; removing the projecting portion of said interlayer insulating film by etching.
Claim 10
Independent Claim
152 words
A method for fabricating a semiconductor device comprising the steps of: forming a semiconductor film on an insulating surface, said semiconductor film having at least channel, source and drain regions therein; forming a first insulating film on said semiconductor film; forming an interlayer insulating film over said semiconductor film and said first insulating film, said interlayer insulating film comprising a different material from said first insulating film; forming a first opening in said interlayer insulating film by etching to expose a portion of said first insulating film in said first opening; forming a second opening in said first insulating film in order to expose a portion of said semiconductor film by etching the portion of said first insulating film exposed in said first opening using a liquid etchant whereby a portion of said interlayer insulating film projects over said second opening; removing the projecting portion of said interlayer insulating film by etching.
Claim 11
Dependent Claim
14 words
The method according to claim 8, wherein said first insulating film comprises silicon oxide.
Claim 12
Dependent Claim
25 words
The method according to claim 8, wherein said interlayer insulating film comprises a material selected from the group consisting of silicon nitride and organic resin.
Claim 13
Dependent Claim
25 words
The method according to claim 8, wherein said interlayer insulating film comprises at least two laminated layers including an upper layer and a lower layer.
Claim 14
Dependent Claim
28 words
The method according to claim 11, wherein said first opening has a tapered configuration and said upper layer has a higher degree of tapering than said lower layer.
Claim 15
Dependent Claim
14 words
The method according to claim 8, wherein said liquid etchant comprises buffered hydrofluoric acid.
Claim 16
Dependent Claim
27 words
The method according to claim 8, wherein the etching of said projecting portion is conducted by dry etching with an etching gas comprising carbon tetrafluoride and oxygen.
Claim 17
Independent Claim
191 words
A method for fabricating a semiconductor device comprising the steps of: forming a semiconductor film on an insulating surface, said semiconductor film having at least channel, source and drain regions therein; forming a first insulating film on said semiconductor film; forming a second insulating film on said first insulating film, said second insulating film comprising a different material from said first insulating film; forming a first opening in said second insulating film by first dry etching using a first etching gas containing oxygen to expose a portion of said first insulating film in said first opening; forming a second opening in said first insulating film in order to expose a portion of said semiconductor film by etching the portion of said first insulating film exposed in said first opening using a liquid etchant whereby a portion of said second insulating film projects over said second opening; removing the projecting portion of said second insulating film by second dry etching using a second etching gas containing oxygen, and wherein a proportion of the oxygen in said second etching gas is higher than a proportion of the oxygen in said first etching gas.
Claim 18
Independent Claim
191 words
A method for fabricating a semiconductor device comprising the steps of: forming a semiconductor film on an insulating surface, said semiconductor film having at least channel, source and drain regions therein; forming a first insulating film on said semiconductor film; forming a second insulating film on said first insulating film, said second insulating film comprising a different material from said first insulating film; forming a first opening in said second insulating film by first dry etching using a first etching gas containing oxygen to expose a portion of said first insulating film in said first opening; forming a second opening in said first insulating film in order to expose a portion of said semiconductor film by etching the portion of said first insulating film exposed in said first opening using a liquid etchant whereby a portion of said second insulating film projects over said second opening; removing the projecting portion of said second insulating film by second dry etching using a second etching gas containing oxygen, and wherein a proportion of the oxygen in said second etching gas is higher than a proportion of the oxygen in said first etching gas.
Claim 19
Dependent Claim
14 words
The method according to claim 15, wherein said first insulating film comprises silicon oxide.
Claim 20
Dependent Claim
25 words
The method according to claim 15, wherein said second insulating film comprises a material selected from the group consisting of silicon nitride and organic resin.
Claim 21
Dependent Claim
25 words
The method according to claim 15, wherein said second insulating film comprises at least two laminated layers including an upper layer and a lower layer.
Claim 22
Dependent Claim
27 words
The method according to claim 18, wherein said first opening has tapered configuration and said upper layer has a higher degree of tapering than said lower layer.
Claim 23
Dependent Claim
14 words
The method according to claim 15, wherein said liquid etchant comprises buffered hydrofluoric acid.
Claim 24
Dependent Claim
21 words
The method according to claim 15, wherein each of said first and second etching gas comprises said oxygen and carbon tetrafluoride.
Claim 25
Independent Claim
146 words
A method for fabricating a semiconductor device comprising the steps of: forming a semiconductor film on an insulating surface, said semiconductor film having at least channel, source and drain regions therein; forming a first insulating film on said semiconductor film; forming an interlayer insulating film consisting of a plurality of insulating layers over said semiconductor film and said first insulating film; first etching said interlayer insulating film to expose a portion of said first insulating film in an opening; second etching the portion of said first insulating film exposed by said first etching to expose a portion of said semiconductor film in said opening, whereby a portion of said interlayer insulating film projects over said opening; and removing the projecting portion of said interlayer insulating film by etching, wherein at least one of said plurality of insulating layers in said interlayer insulating layer comprises organic resin.
Claim 26
Independent Claim
146 words
A method for fabricating a semiconductor device comprising the steps of: forming a semiconductor film on an insulating surface, said semiconductor film having at least channel, source and drain regions therein; forming a first insulating film on said semiconductor film; forming an interlayer insulating film consisting of a plurality of insulating layers over said semiconductor film and said first insulating film; first etching said interlayer insulating film to expose a portion of said first insulating film in an opening; second etching the portion of said first insulating film exposed by said first etching to expose a portion of said semiconductor film in said opening, whereby a portion of said interlayer insulating film projects over said opening; and removing the projecting portion of said interlayer insulating film by etching, wherein at least one of said plurality of insulating layers in said interlayer insulating layer comprises organic resin.
Claim 27
Dependent Claim
14 words
The method according to claim 22 wherein said first insulating film comprises silicon oxide.
Claim 28
Dependent Claim
23 words
The method according to claim 22 wherein another one of said plurality of insulating layers in said interlayer insulating layer comprises silicon nitride.
Claim 29
Dependent Claim
20 words
The method according to claim 22 wherein said second etching is performed using said liquid etchant comprising buffered hydrofluoric acid.
Claim 30
Dependent Claim
27 words
The method according to claim 22 wherein the removing of said projecting portion is conducted by dry etching with an etching gas comprising carbon tetrafluoride and oxygen.
Claim 31
Dependent Claim
28 words
The method according to claim 22 wherein said source and drain regions are doped with phosphorus at a dose of 0.2 to 5×10 15 atoms/cm 2 , respectively.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2002-08-16 | 2003-02-15 | 2003-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-08-16 | 2007-02-15 | 2007-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-08-16 | 2011-02-15 | 2011-08-17 | $7700.00 | Window Closed / Lapsed |