US4942137A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-aligned trench with selective trench fill
Assignee: Motorola Solutions Inc
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Filing: 1989-08-14
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Granted: 1990-07-17
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Expires: 2009-08-14
Abstract
Abstract A method for fabricating a self-aligned trench structure in a semiconductor device is disclosed. In accordance with one method for fabricating the trench structure, an oxidation resistant material having an opening is used as a masking layer. The edge of the opening in the masking layer is covered by a sidewall spacer which protects a portion of the substrate from attack by the etchant used to form the trench. The trench is filled with a trench fill material by selective deposition using a seeding material formed on the sidewall of the trench as a nucleation site. After the trench is filled, the sidewall spacer is removed and the underlying substrate is oxidized to form an electrical insulation region around the upper portion of the trench. The mask layer is removed and the remaining substrate is doped using the insulation region surrounding the trench as a dopant mask.
Inventors
- 👤 Richard D. Sivan
- 👤 James R. Pfiester
- 👤 John E. Leiss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:57
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/61; H10P50/00; H10P50/69; H10P50/691; H10P50/693; H10P50/695; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/014; H10W10/0145; H10W10/0147; H10W10/041; H10W10/10; H10W10/17; H10W10/40
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
181 words
A method for fabricating an integrated circuit trench structure, comprising the steps of: providing a substrate having a surface; forming a masking layer over said substrate surface; forming an opening in said masking layer overlying said substrate surface, said opening bounded by a vertical surface and exposing a portion of said substrate surface; forming a sidewall spacer on said vertical surface, said sidewall spacer covering an edge portion of said exposed substrate surface and leaving exposed a central portion of said exposed substrate surface; etching a trench in said exposed central portion of said exposed substrate surface, using said sidewall spacer as an etch mask, said trench having a wall surface and a bottom surface, said wall surface being self-aligned with said sidewall spacers; depositing a material into and substantially filling said trench; removing said sidewall spacers to expose said edge portion of said exposed substrate surface; thermally oxidizing said edge portion to form an insulating region overlying said edge portion of said exposed substrate surface and surrounding said central portion of said exposed substrate surface; and removing said masking layer.
Claim 2
Independent Claim
181 words
A method for fabricating an integrated circuit trench structure, comprising the steps of: providing a substrate having a surface; forming a masking layer over said substrate surface; forming an opening in said masking layer overlying said substrate surface, said opening bounded by a vertical surface and exposing a portion of said substrate surface; forming a sidewall spacer on said vertical surface, said sidewall spacer covering an edge portion of said exposed substrate surface and leaving exposed a central portion of said exposed substrate surface; etching a trench in said exposed central portion of said exposed substrate surface, using said sidewall spacer as an etch mask, said trench having a wall surface and a bottom surface, said wall surface being self-aligned with said sidewall spacers; depositing a material into and substantially filling said trench; removing said sidewall spacers to expose said edge portion of said exposed substrate surface; thermally oxidizing said edge portion to form an insulating region overlying said edge portion of said exposed substrate surface and surrounding said central portion of said exposed substrate surface; and removing said masking layer.
Claim 3
Dependent Claim
34 words
The method of claim 1 further comprising the steps of; forming a channel stop layer in said exposed substrate; and forming a passivation layer overlying said trench wall surface and said trench bottom surface.
Claim 4
Dependent Claim
55 words
The method of claim 2 wherein said step of depositing comprises the steps of: forming a layer of a first material on said passivation layer; and selectively depositing a layer of a second material into and substantially filling said trench using said layer of first material as a nucleation site for said selective deposition therein.
Claim 5
Dependent Claim
69 words
The method of claim 3 wherein said step of forming a layer of a first material comprises the steps of: conformably depositing a first layer of conductive material to overlie said passivation layer, said first layer of conductive material being differentially etchable with respect to said passivation layer; and anisotropically etching said first layer of conductive material to leave a portion of said first layer on said passivation layer.
Claim 6
Dependent Claim
23 words
The method of claim 4 wherein said conductive material is selected from the group consisting of polycrystalline silicon, tungsten, platinum, cobalt, and titanium.
Claim 7
Dependent Claim
23 words
The method of claim 3 wherein said first material is selected from the group consisting of polycrystalline silicon, tungsten, platinum, cobalt, and titanium.
Claim 8
Dependent Claim
23 words
The method of claim 3 wherein said second material is selected from the group consisting of polycrystalline silicon, tungsten, platinum, cobalt, and titanium.
Claim 9
Dependent Claim
59 words
The method of claim 2 wherein said step of providing a substrate and said step of forming a masking layer comprises the steps of: providing a single crystal silicon substrate oxidizing said single crystal silicon substrate to form a thin layer of silicon dioxide overlying said substrate; and depositing a layer of silicon nitride to overlie said thin layer.
Claim 10
Dependent Claim
36 words
The method of claim 2 wherein said step of providing a substrate comprises the steps of: providing a single crystal silicon substrate; and depositing a layer of epitaxial silicon to overlie said single crystal silicon substrate.
Claim 11
Dependent Claim
21 words
The method of claim 2 wherein said step of forming a passivation layer comprises the step of depositing a dielectric material.
Claim 12
Dependent Claim
27 words
The method of claim 2 wherein said step of forming a passivation layer comprises the step of thermally oxidizing silicon to from a layer of silicon dioxide.
Claim 13
Dependent Claim
56 words
The method of claim 1 wherein said step of depositing comprises the steps of: forming a layer of a first material on said trench wall surface; and selectively depositing a layer of a second material into and substantially filling said trench using said layer of first material as a nucleation site for said selective deposition therein.
Claim 14
Dependent Claim
76 words
The method of claim 12 wherein said step of forming a layer of a first material comprises the steps of: conformably depositing a first layer of conductive material to overlie said trench wall surface, said first layer of conductive material being differentially etchable with respect to said trench wall surface and said trench bottom surface; and anisotropically etching said first layer of conductive material to leave a portion of said first layer on said trench wall.
Claim 15
Dependent Claim
23 words
The method of claim 13 wherein said conductive material is selected from the group consisting of polycrystalline silicon, tungsten, platinum, cobalt, and titanium.
Claim 16
Dependent Claim
23 words
The method of claim 12 wherein said first material is selected from the group consisting of polycrystalline silicon, tungsten, platinum, cobalt, and titanium.
Claim 17
Dependent Claim
23 words
The method of claim 12 wherein said second material is selected from the group consisting of polycrystalline silicon, tungsten, platinum, cobalt, and titanium.
Claim 18
Dependent Claim
17 words
The method of claim 1 wherein said step of depositing a material comprises depositing a dielectric material.
Claim 19
Dependent Claim
59 words
The method of claim 1 wherein said step of providing a substrate and said step of forming a masking layer comprises the steps of: providing a single crystal silicon substrate oxidizing said single crystal silicon substrate to form a thin layer of silicon dioxide overlying said substrate; and depositing a layer of silicon nitride to overlie said thin layer.
Claim 20
Dependent Claim
36 words
The method of claim 1 wherein said step of providing a substrate comprises the steps of: providing a single crystal silicon substrate; and depositing a layer of epitaxial silicon to overlie said single crystal silicon substrate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-16 | 1994-01-15 | 1994-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-16 | 1998-01-15 | 1998-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-16 | 2002-01-15 | 2002-07-17 | $7700.00 | Window Closed / Lapsed |