US5702976A
Expired / Lapsed
US
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Shallow trench isolation using low dielectric constant insulator
Assignee: Round Rock Research LLC
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Filing: 1995-10-24
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Granted: 1997-12-30
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Expires: 2015-10-24
Abstract
Abstract A shallow trench isolation is disclosed wherein the trench depth is reduced beyond that achieved in prior art processes. The reduced wench depth helps to eliminate the formation of voids during the trench refill process and provides for greater planarity in the final isolation structure. Effective device isolation is achieved with a reduced trench depth by utilizing refilling dielectric materials having low dielectric constant.
Inventors
- 👤 Klaus F. Schuegraf
- 👤 Aftab Ahmad
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:29
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/014; H10W10/10; H10W10/17; Y; Y10; Y10S; Y10S148/00; Y10S148/05
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
57 words
A process for isolating devices on a semiconductor substrate comprising the steps of: removing predetermined portions of the semiconductor substrate forming recesses therein; and refilling the portions of the semiconductor substrate with a material comprising an in situ doped silicon oxide complex, the material having a dielectric constant lower than the dielectric constant of undoped silicon dioxide.
Claim 2
Dependent Claim
57 words
A process for isolating devices on a semiconductor substrate comprising the steps of: removing predetermined portions of the semiconductor substrate forming recesses therein; and refilling the portions of the semiconductor substrate with a material comprising an in situ doped silicon oxide complex, the material having a dielectric constant lower than the dielectric constant of undoped silicon dioxide.
Claim 3
Dependent Claim
22 words
The process of claim 1, wherein the step of removing portions of the semiconductor wafer comprises forming trenches in the semiconductor wafer.
Claim 4
Dependent Claim
16 words
The process of claim 2, wherein the trenches have a depth of less than 200 nm.
Claim 5
Dependent Claim
16 words
The process of claim 3, wherein the trenches have an aspect ratio of less than 2:1.
Claim 6
Dependent Claim
65 words
A process for isolating devices on a semiconductor substrate comprising the steps of: removing predetermined portions of the semiconductor substrate forming recesses therein; and refilling the portions of the semiconductor substrate with a material having a dielectric constant lower than the dielectric constant of silicon dioxide, wherein the material having a dielectric constant lower than that of silicon dioxide comprises a halide-doped silicon dioxide composition.
Claim 7
Dependent Claim
65 words
A process for isolating devices on a semiconductor substrate comprising the steps of: removing predetermined portions of the semiconductor substrate forming recesses therein; and refilling the portions of the semiconductor substrate with a material having a dielectric constant lower than the dielectric constant of silicon dioxide, wherein the material having a dielectric constant lower than that of silicon dioxide comprises a halide-doped silicon dioxide composition.
Claim 8
Dependent Claim
17 words
The process of claim 5, wherein the halide-doped silicon dioxide complex comprises a Fluorine-doped silicon dioxide complex.
Claim 9
Dependent Claim
17 words
The process of claim 1, wherein the refilling material has a dielectric constant less than about 3.9.
Claim 10
Dependent Claim
26 words
The process of claim 1, further comprising forming a barrier layer over the semiconductor substrate prior to the step of refilling portions of the semiconductor substrate.
Claim 11
Dependent Claim
14 words
The process of claim 8, wherein the barrier layer comprises a silicon dioxide composition.
Claim 12
Dependent Claim
14 words
The process of claim 8, wherein the barrier layer comprises a silicon nitride composition.
Claim 13
Independent Claim
38 words
A method of reducing the formation of voids in a refilled trench isolation process comprising the steps of: forming trenches having an aspect ratio less than 2:1; refilling the trenches with an insulating material; and halide-doping the material.
Claim 14
Independent Claim
38 words
A method of reducing the formation of voids in a refilled trench isolation process comprising the steps of: forming trenches having an aspect ratio less than 2:1; refilling the trenches with an insulating material; and halide-doping the material.
Claim 15
Dependent Claim
16 words
The method of claim 11, wherein the trenches have a depth of less than 200 nm.
Claim 16
Independent Claim
56 words
A method of reducing the formation of voids in a refilled trench isolation process comprising the steps of: forming trenches having an aspect ratio less than 2:1; and refilling the trenches with a material having a dielectric constant less than the dielectric constant of silicon dioxide, wherein the refilling material comprises a Fluorine-doped silicon dioxide composition.
Claim 17
Independent Claim
56 words
A method of reducing the formation of voids in a refilled trench isolation process comprising the steps of: forming trenches having an aspect ratio less than 2:1; and refilling the trenches with a material having a dielectric constant less than the dielectric constant of silicon dioxide, wherein the refilling material comprises a Fluorine-doped silicon dioxide composition.
Claim 18
Dependent Claim
18 words
The method of claim 11, wherein the halide-doped material has a dielectric constant of less than about 3.9.
Claim 19
Dependent Claim
12 words
The method of claim 1, wherein the material comprises a halide-doped oxide.
Claim 20
Dependent Claim
12 words
The method of claim 1, wherein the material comprises a fluoride-doped oxide.
Claim 21
Dependent Claim
13 words
The method of claim 11, wherein refilling the trenches comprises depositing silicon dioxide.
Claim 22
Dependent Claim
14 words
The method of claim 17, wherein depositing silicon dioxide comprises a chemical vapor deposition.
Claim 23
Dependent Claim
21 words
The method of claim 18, wherein halide-doping the material comprises in situ halide doping during chemical vapor deposition of the material.
Claim 24
Dependent Claim
20 words
The method of claim 11, wherein doping the material comprises introducing a halide into the material while refilling the trenches.
Claim 25
Dependent Claim
10 words
The method of claim 11, wherein the halide comprises fluorine.
Claim 26
Dependent Claim
35 words
A process for isolating devices on a semiconductor substrate comprising the steps of: forming trenches within the substrate; lining the trenches with a diffusion barrier; refilling the trenches with silicon dioxide; and halide-doping silicon dioxide.
Claim 27
Dependent Claim
35 words
A process for isolating devices on a semiconductor substrate comprising the steps of: forming trenches within the substrate; lining the trenches with a diffusion barrier; refilling the trenches with silicon dioxide; and halide-doping silicon dioxide.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 2000-12-29 | 2001-06-30 | 2001-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-12-29 | 2005-06-30 | 2005-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-12-29 | 2009-06-30 | 2009-12-30 | $7700.00 | Window Closed / Lapsed |