US5804491A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combined field/trench isolation region fabrication methods
Assignee: Mosaid Technologies Inc
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Filing: 1996-11-08
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Granted: 1998-09-08
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Expires: 2016-11-08
Abstract
Abstract Isolation regions are fabricated on a substrate by forming a pattern region on the substrate, exposing spaced apart first and second areas of the substrate. The second area is then covered, preferably using sidewall spacers formed adjacent sidewall portions of the pattern region, while a portion of the first area is left exposed. A first insulation region is then formed on the exposed portion of the first area. The second area is then exposed and a trench isolation region is formed at the second area. Preferably, the pattern region is formed by forming a masking layer on the substrate and patterning the masking layer using a single photolithographic mask. The first insulation layer preferably is formed by thermally oxidizing the exposed portion of the first area. Preferably, the first area is wider than the second area.
Inventors
- 👤 Dong-ho Ahn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:31
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/012; H10W10/014; H10W10/0145; H10W10/10; H10W10/13; H10W10/17
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
85 words
A method of fabricating isolation regions on a substrate, the method comprising the steps of: forming a pattern region on the substrate, exposing spaced apart first and second areas of the substrate; covering the second area while leaving exposed at least a portion of the first area; thermally oxidizing the exposed portion of the first area to thereby form a first insulation region on the exposed portion of the first area; exposing the second area; and forming a trench isolation region at the second area.
Claim 2
Independent Claim
85 words
A method of fabricating isolation regions on a substrate, the method comprising the steps of: forming a pattern region on the substrate, exposing spaced apart first and second areas of the substrate; covering the second area while leaving exposed at least a portion of the first area; thermally oxidizing the exposed portion of the first area to thereby form a first insulation region on the exposed portion of the first area; exposing the second area; and forming a trench isolation region at the second area.
Claim 3
Dependent Claim
35 words
A method according to claim 1 wherein said step of forming a pattern region comprises the steps of: forming a masking layer on the substrate; and patterning the masking layer using a single photolithographic mask.
Claim 4
Dependent Claim
35 words
A method according to claim 1 wherein said step of forming a first insulation region comprises the step of thermally oxidizing the exposed portion of the first area to thereby form the first insulation region.
Claim 5
Dependent Claim
16 words
A method according to claim 1 wherein the first area is wider than the second area.
Claim 6
Independent Claim
104 words
A method of fabricating isolation regions on a substrate, the method comprising the steps of: forming a pattern region on the substrate exposing spaced apart first and second areas of the substrate; covering the second area while leaving exposed at least a portion of the first area; forming a first insulation region on the exposed portion of the first area; exposing the second area; forming a trench in the substrate at the second area; forming an insulation layer filling the trench and covering the pattern region and the first insulation region; and planarizing the substrate to form a second insulation region in the trench.
Claim 7
Independent Claim
104 words
A method of fabricating isolation regions on a substrate, the method comprising the steps of: forming a pattern region on the substrate exposing spaced apart first and second areas of the substrate; covering the second area while leaving exposed at least a portion of the first area; forming a first insulation region on the exposed portion of the first area; exposing the second area; forming a trench in the substrate at the second area; forming an insulation layer filling the trench and covering the pattern region and the first insulation region; and planarizing the substrate to form a second insulation region in the trench.
Claim 8
Dependent Claim
30 words
A method according to claim 5, wherein said step of forming an insulation layer is preceded by the step of thermally oxidizing exposed portions of the substrate in the trench.
Claim 9
Dependent Claim
86 words
A method according to claim 5: wherein said step of forming a pattern region comprises the steps of: forming a barrier layer on the substrate; forming a first insulation layer on the barrier layer; and patterning the barrier layer and the first insulation layer to form a pattern region on the substrate, exposing spaced apart first and second areas of the substrate; wherein said step of planarizing the substrate comprises the step of chemical mechanical polishing the substrate using the barrier layer as a polishing stop.
Claim 10
Dependent Claim
86 words
A method according to claim 5: wherein said step of forming a pattern region comprises the steps of: forming a barrier layer on the substrate; forming a first insulation layer on the barrier layer; and patterning the barrier layer and the first insulation layer to form a pattern region on the substrate, exposing spaced apart first and second areas of the substrate; wherein said step of planarizing the substrate comprises the step of reactive ion etching the substrate using the barrier layer as an etching stop.
Claim 11
Dependent Claim
65 words
A method according to claim 1: wherein said step of covering the second area comprises the step of forming sidewall spacers adjacent sidewall portions of the pattern region, covering the second area and leaving exposed a portion of the first area between sidewall spacers; and wherein said step of exposing the second area comprises the step of removing the sidewall spacers covering the second area.
Claim 12
Dependent Claim
23 words
A method according to claim 1 wherein the substrate includes a silicon region and a silicon dioxide layer at an upper surface thereof.
Claim 13
Independent Claim
88 words
A method of fabricating isolation regions on a substrate, the method comprising the steps of: forming a pattern region on the substrate, exposing spaced apart first, second and third areas of the substrate; covering the second and third areas while leaving exposed at least a portion of the first area; forming a first insulation region on the exposed portion of the first area; exposing the second and third areas; and forming a trench isolation region in the substrate, the trench isolation region spanning the second and third areas.
Claim 14
Independent Claim
88 words
A method of fabricating isolation regions on a substrate, the method comprising the steps of: forming a pattern region on the substrate, exposing spaced apart first, second and third areas of the substrate; covering the second and third areas while leaving exposed at least a portion of the first area; forming a first insulation region on the exposed portion of the first area; exposing the second and third areas; and forming a trench isolation region in the substrate, the trench isolation region spanning the second and third areas.
Claim 15
Dependent Claim
35 words
A method according to claim 11 wherein said step of forming a pattern region comprise the steps of: forming a masking layer on the substrate; and patterning the masking layer using a single photolithographic mask.
Claim 16
Dependent Claim
35 words
A method according to claim 11 wherein said step of forming a first insulation region comprises the step of thermally oxidizing the exposed portion of the first area to thereby form the first insulation region.
Claim 17
Dependent Claim
18 words
A method according to claim 11 wherein the first area is wider than the second and third areas.
Claim 18
Dependent Claim
64 words
A method according to claim 11 wherein said step of forming a trench isolation region comprises the steps of: forming two spaced apart trenches, each of the trenches being formed at a respective one of the second and third areas; removing portions of the substrate between the two trenches to form a single trench; and forming a second insulation region in the single trench.
Claim 19
Dependent Claim
51 words
A method according to claim 15, wherein said step of forming a second insulation region comprises the steps of: forming an insulation layer filling the single trench and covering the pattern region and the first insulation region; and planarizing the substrate to form a second insulation region in the single trench.
Claim 20
Dependent Claim
31 words
A method according to claim 16, wherein said step of forming an insulation layer is preceded by the step of thermally oxidizing exposed portions of the substrate in the single trench.
Claim 21
Dependent Claim
87 words
A method according to claim 16: wherein said step of forming a pattern region comprises the steps of: forming a barrier layer on the substrate; forming a first insulation layer on the barrier layer; and patterning the barrier layer and the first insulation layer to form a pattern region on the substrate, exposing spaced apart first, second and third areas of the substrate; wherein said step of planarizing the substrate comprises the step of chemical mechanical polishing the substrate using the barrier layer as a polishing stop.
Claim 22
Dependent Claim
87 words
A method according to claim 16: wherein said step of forming a pattern region comprises the steps of: forming a barrier layer on the substrate; forming a first insulation layer on the barrier layer; and patterning the barrier layer and the first insulation layer to form a pattern region on the substrate, exposing spaced apart first, second and third areas of the substrate; wherein said step of planarizing the substrate comprises the step of reactive ion etching the substrate using the barrier layer as an etching stop.
Claim 23
Dependent Claim
75 words
A method according to claim 11: wherein said step of covering the second and third areas comprises the step of forming sidewall spacers adjacent sidewall portions of the pattern region, covering the second and third areas and leaving exposed at least a portion of the first area between sidewall spacers; and wherein said step of exposing the second and third areas comprises the step of removing the sidewall spacers covering the second and third areas.
Claim 24
Dependent Claim
23 words
A method according to claim 11 wherein the substrate includes a silicon region and a silicon dioxide layer at an upper surface thereof.
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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) | 2001-09-07 | 2002-03-09 | 2002-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-07 | 2006-03-09 | 2006-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-07 | 2010-03-09 | 2010-09-08 | $7700.00 | Window Closed / Lapsed |