US4980311A
Expired / Lapsed
US
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Method of fabricating a semiconductor device
Assignee: Seiko Epson Corp
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Filing: 1988-11-23
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Granted: 1990-12-25
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Expires: 2008-11-23
Abstract
Abstract A semiconductor device and method of fabrication thereof includes both narrow and wide element isolation regions which have been fabricated employing a trench isolation technique. The technique allows for the production of wide element isolation regions in submicron semiconductor devices wherein the entire wide element isolation region is covered with an insulating material.
Inventors
- 👤 Isamu Namose
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 02:21
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/014; H10W10/0142; H10W10/0148; H10W10/10; H10W10/17
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
80 words
A method for fabricating a semiconductor device comprising: forming trenches within a substrate of the device wherein at least one of the trenches encloses a predetermined portion of the substrate; disposing insulating film within the trenches; forming a first mask over the substrate except for that area encompassed by the predetermined portion; oxidizing the substrate to form an oxide film over the predetermined portion; and creating a plurality of narrow and wide element isolating regions in and on the substrate.
Claim 2
Independent Claim
80 words
A method for fabricating a semiconductor device comprising: forming trenches within a substrate of the device wherein at least one of the trenches encloses a predetermined portion of the substrate; disposing insulating film within the trenches; forming a first mask over the substrate except for that area encompassed by the predetermined portion; oxidizing the substrate to form an oxide film over the predetermined portion; and creating a plurality of narrow and wide element isolating regions in and on the substrate.
Claim 3
Dependent Claim
24 words
The method of claim 1, wherein the trenches are formed in accordance with the configuration of an additional mask comprising an anti-anisotropic etching film.
Claim 4
Dependent Claim
19 words
The method of claim 2, wherein the trenches are formed by anisotropic etching of the additional mask and substrate.
Claim 5
Dependent Claim
18 words
The method of claim 3, wherein the trenches are formed by reactive ion etching using CBrF 3 .
Claim 6
Dependent Claim
27 words
The method of claim 4, wherein the additional mask comprises a material selected from the group consisting of photoresist, SiO 2 and Si 3 N 4 .
Claim 7
Dependent Claim
28 words
The method of claim 1, wherein the insulating film is disposed within the trenches and on the surface of the substrate by chemical vapor deposition of silicon oxide.
Claim 8
Dependent Claim
13 words
The method of claim 1, wherein the first mask comprises an anti-oxidation film.
Claim 9
Dependent Claim
61 words
The method of claim 7, wherein the first mask is formed by vapor growth of a silicon nitride film over the insulting film, placing a thermal plastic material over the silicon nitride film except over that area encompassing the predetermined portion, removing that portion of the silicon nitride film which overlays the predetermined portion and finally removing the thermal plastic material.
Claim 10
Dependent Claim
21 words
The method of claim 7, wherein the anti-oxidation film has an end portion formed on the insulating film within the trenches.
Claim 11
Dependent Claim
25 words
The method of claim 1, wherein the substrate is oxidized under a wet oxygen atmosphere at approximately eight atmospheres of pressure for approximately one hour.
Claim 12
Dependent Claim
22 words
The method of claim 1, wherein the isolating regions are created by removing the first mask from all portions of the substrate.
Claim 13
Dependent Claim
18 words
The method of claim 1, further comprising providing stopper regions at least at the bottom of the trenches.
Claim 14
Dependent Claim
14 words
The method of claim 12, wherein the stopper regions are created by ion implantation.
Claim 15
Dependent Claim
20 words
The method of claim 13, wherein the ions implanted are selected from the group consisting of boron, phosphorous and arsenic.
Claim 16
Dependent Claim
14 words
The method of claim 1, further comprising disposing polycrystalline silicon film within the trenches.
Claim 17
Dependent Claim
18 words
The method of claim 14, wherein the polycrystalline silicon film is disposed below the surface of the substrate.
Claim 18
Dependent Claim
106 words
The method of claim 16, wherein the insulating film is further disposed on the surface of the substrate; and wherein the first mask is formed first by vapor growth of silicon nitride film over the insulating film followed by disposition of the polycrystalline film within the trenches whereby the silicon nitride film is sandwiched between the insulating film and the polycrystalline silicon film followed by formation of an additional mask over the silicon nitride film except for that area encompassing the predetermined portion followed by removal of the silicon nitride film over that area encompassing the predetermined portion and finally by removal of the additional mask.
Claim 19
Dependent Claim
54 words
The method of claim 17, wherein the additional mask is selected from the group of materials consisting of photoresist film and boron phosphorous silicate glass and is removed by plasma etching using oxygen; and the silicon nitride film is removed from the area encompassing the predetermined portion by plasma etching using CF 4 gas.
Claim 20
Dependent Claim
17 words
The method of claim 16, further comprising oxidizing the polycrystalline silicon film to form silicon oxide film.
Claim 21
Dependent Claim
24 words
The method of claim 19, wherein the isolating regions are created by removing all portions of the first mask which extend outside the trenches.
Claim 22
Dependent Claim
29 words
The method of claim 19, further comprising thermally oxidizing the polycrystalline silicon at a temperature of about 950° C., at about eight atmospheres of pressure for about four hours.
Claim 23
Dependent Claim
30 words
The method of claim 15, wherein the polycrystalline silicon film is disposed only within the trenches by first disposing a film of polycrystalline silicon over the entire silicon nitride film.
Claim 24
Dependent Claim
29 words
The method of claim 22, wherein the polycrystalline silicon film is removed from the surface substrate and partially from within the trenches by plasma etching using CF 4 gas.
Claim 25
Independent Claim
156 words
A method of fabricating a semiconductor device comprising: forming a first mask over a substrate of the device; etching the substrate to form trenches in accordance with the configuration of the first mask wherein one of said trenches encloses a predetermined portion of the substrate; removing the first mask; depositing an insulating film of silicon oxide within the trenches and on the surface of the substrate; depositing an anti-oxidation mask of silicon nitride film over the insulating film; forming a second mask over the silicon nitride film except for those portions of the silicon nitride film overlaying the predetermined portion; removing that portion of the silicon nitride film covering the predetermined portion to expose the insulating film of silicon oxide; removing the second mask; oxidizing the substrate; and removing all remaining portions of the silicon nitride film outside the trenches thereby creating a plurality of narrow and wide element isolating regions in and on the substrate.
Claim 26
Independent Claim
156 words
A method of fabricating a semiconductor device comprising: forming a first mask over a substrate of the device; etching the substrate to form trenches in accordance with the configuration of the first mask wherein one of said trenches encloses a predetermined portion of the substrate; removing the first mask; depositing an insulating film of silicon oxide within the trenches and on the surface of the substrate; depositing an anti-oxidation mask of silicon nitride film over the insulating film; forming a second mask over the silicon nitride film except for those portions of the silicon nitride film overlaying the predetermined portion; removing that portion of the silicon nitride film covering the predetermined portion to expose the insulating film of silicon oxide; removing the second mask; oxidizing the substrate; and removing all remaining portions of the silicon nitride film outside the trenches thereby creating a plurality of narrow and wide element isolating regions in and on the substrate.
Claim 27
Independent Claim
121 words
A method of fabricating a semiconductor device comprising: etching the substrate to form trenches wherein one of said trenches encloses a predetermined portion of the substrate; depositing an insulating film of silicon oxide within the trenches and on the surface of the substrate; depositing an anti-oxidation mask of silicon nitride film over the insulating film; depositing a film of polycrystalline silicon over the anti-oxidation mask; coating the polycrystalline silicon film with a photoresist material; etching all of the photoresist material except that portion overlaying at least one of the trenches; removing all of the polycrystalline silicon film overlaying the surface of the substrate; removing a portion of the polycrystalline film within each of the trenches; and removing the remaining photoresist material.
Claim 28
Independent Claim
121 words
A method of fabricating a semiconductor device comprising: etching the substrate to form trenches wherein one of said trenches encloses a predetermined portion of the substrate; depositing an insulating film of silicon oxide within the trenches and on the surface of the substrate; depositing an anti-oxidation mask of silicon nitride film over the insulating film; depositing a film of polycrystalline silicon over the anti-oxidation mask; coating the polycrystalline silicon film with a photoresist material; etching all of the photoresist material except that portion overlaying at least one of the trenches; removing all of the polycrystalline silicon film overlaying the surface of the substrate; removing a portion of the polycrystalline film within each of the trenches; and removing the remaining photoresist material.
Claim 29
Dependent Claim
76 words
The method of claim 25, further comprising disposing additional photoresist material covering the silicon nitride film except for those areas overlaying the predetermined portion; removing the silicon nitride film overlaying the predetermined portion to expose the insulating film of silicon oxide; removing the additional photoresist material; oxidizing the substrate; and removing the remaining silicon nitride film outside the trenches whereby a plurality of narrow and wide element isolating regions in and on the substrate are created.
Claim 30
Dependent Claim
88 words
The method of claim 25, further comprising oxidizing the polycrystalline film disposed within the trenches to form silicon oxide; disposing additional photoresist material over the silicon nitride film except for those areas above the predetermined portion; removing the silicon nitride film overlaying the predetermined portion to expose the insulating film of silicon oxide; removing the additional photoresist material; oxidizing the substrate; and removing the remaining silicon nitride film outside the trenches whereby a plurality of narrow and wide element isolating regions in and on the substrate are created.
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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) | 1993-12-24 | 1994-06-25 | 1994-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-24 | 1998-06-25 | 1998-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-24 | 2002-06-25 | 2002-12-25 | $7700.00 | Window Closed / Lapsed |