Patent US5915192A successfully refreshed from Google Patents.
US5915192A
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Method for forming shallow trench isolation
Assignee: Abbott Laboratories Vascular Enterprises Ltd
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Filing: 1997-09-12
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Granted: 1999-06-22
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Expires: 2017-09-12
Abstract
Abstract A method of forming a trench isolation is disclosed. The initial step includes forming a first dielectric layer on a substrate of a transistor followed by a second dielectric layer formed on the first dielectric layer. Next, the substrate, the first dielectric layer and the second dielectric layer is patterned and etched to form a trench in the substrate, the first dielectric layer and the second dielectric layer. Next, a third dielectric layer is formed on the surface of the side wall of the trench followed by isotropically etching the bottom of the trench. Finally, a fourth dielectric layer on the surface of the trench is formed and the trench is filled with a dielectric material.
Inventors
- 👤 Jhon-Jhy Liaw
- 👤 Jin-Yuan Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:56
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/014; H10W10/0145; H10W10/10; H10W10/17; Y; Y10; Y10S; Y10S148/00; Y10S148/05
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
114 words
A method of forming a trench isolation comprising the steps of: forming a first dielectric layer on a substrate of a transistor; forming a second dielectric layer on said first dielectric layer; patterning and etching said substrate, said first dielectric layer and said second dielectric layer to form a trench in said substrate, said first dielectric layer and said second dielectric layer; forming a third dielectric layer on the surface of the side wall of said trench; isotropically etching the bottom of said trench to expand a portion of said trench; forming a fourth dielectric layer on the surface of said trench and said expanded portion; and refilling said trench with a dielectric material.
Claim 2
Independent Claim
114 words
A method of forming a trench isolation comprising the steps of: forming a first dielectric layer on a substrate of a transistor; forming a second dielectric layer on said first dielectric layer; patterning and etching said substrate, said first dielectric layer and said second dielectric layer to form a trench in said substrate, said first dielectric layer and said second dielectric layer; forming a third dielectric layer on the surface of the side wall of said trench; isotropically etching the bottom of said trench to expand a portion of said trench; forming a fourth dielectric layer on the surface of said trench and said expanded portion; and refilling said trench with a dielectric material.
Claim 3
Dependent Claim
20 words
The method as claim 1, wherein said first dielectric layer is a silicon dioxide layer of 30˜200 angstroms in thickness.
Claim 4
Dependent Claim
25 words
The method as claim 1, wherein said second dielectric layer is a silicon nitride (Si 3 N 4 ) layer of 1500˜3000 angstroms in thickness.
Claim 5
Dependent Claim
16 words
The method as claim 1, wherein said trench is 1500˜3000 angstroms in depth in the substrate.
Claim 6
Dependent Claim
41 words
The method as claim 1, wherein said third dielectric layer is formed comprising the following steps: forming a silicon dioxide layer on the surface of said trench; and removing the portion of said silicon layer on the bottom of said trench.
Claim 7
Dependent Claim
15 words
The method as claim 5, wherein said silicon dioxide layer is 110˜350 angstroms in thickness.
Claim 8
Dependent Claim
21 words
The method as claim 1, wherein the bottom of said trench is isotropically etched by the etchant of SF 6 .
Claim 9
Dependent Claim
19 words
The method as claim 7, wherein the bottom of said trench is isotropically etched for 1000˜3000 angstroms in depth.
Claim 10
Dependent Claim
28 words
The method as claim 1, wherein said method for trench isolation further comprises the step of removing said third dielectric layer before said fourth dielectric layer is formed.
Claim 11
Dependent Claim
15 words
The method as claim 1, wherein said fourth dielectric layer is formed by thermal oxidation.
Claim 12
Dependent Claim
15 words
The method as claim 1, wherein said fourth dielectric layer is 1000˜3000 angstroms in thickness.
Claim 13
Dependent Claim
11 words
The method as claim 1, wherein said dielectric material is polysilicon.
Claim 14
Independent Claim
136 words
A method of forming a trench isolation comprising the steps of: forming a first dielectric layer on a substrate of a transistor; forming a second dielectric layer on said first dielectric layer; patterning and etching said substrate, said first dielectric layer and said second dielectric layer to form a trench in said substrate, said first dielectric layer and said second dielectric layer, said trench extending into said substrate by 1500˜3000 angstroms in depth; forming a third dielectric layer on the surface of the side wall of said trench; isotropically etching the bottom of said trench for 1000˜3000 angstroms in depth; removing said third dielectric layer; forming a fourth dielectric layer on the surface of said trench being isotropically etched, said fourth dielectric layer is formed by thermal oxidation; and refilling said trench with a dielectric material.
Claim 15
Independent Claim
136 words
A method of forming a trench isolation comprising the steps of: forming a first dielectric layer on a substrate of a transistor; forming a second dielectric layer on said first dielectric layer; patterning and etching said substrate, said first dielectric layer and said second dielectric layer to form a trench in said substrate, said first dielectric layer and said second dielectric layer, said trench extending into said substrate by 1500˜3000 angstroms in depth; forming a third dielectric layer on the surface of the side wall of said trench; isotropically etching the bottom of said trench for 1000˜3000 angstroms in depth; removing said third dielectric layer; forming a fourth dielectric layer on the surface of said trench being isotropically etched, said fourth dielectric layer is formed by thermal oxidation; and refilling said trench with a dielectric material.
Claim 16
Dependent Claim
20 words
The method as claim 13, wherein said first dielectric layer is a silicon dioxide layer of 30˜200 angstroms in thickness.
Claim 17
Dependent Claim
25 words
The method as claim 13, wherein said second dielectric layer is a silicon nitride (Si 3 N 4 ) layer of 1500˜3000 angstroms in thickness.
Claim 18
Dependent Claim
41 words
The method as claim 13, wherein said third dielectric layer is formed comprising the following steps: forming a silicon dioxide layer on the surface of said trench; and removing the portion of said silicon layer on the bottom of said trench.
Claim 19
Dependent Claim
15 words
The method as claim 13, wherein said silicon dioxide layer is 110˜350 angstroms in thickness.
Claim 20
Dependent Claim
20 words
The method as claim 13, wherein the bottom of said trench is isotropically etched by the etchant SF 6 .
Claim 21
Dependent Claim
15 words
The method as claim 13, wherein said fourth dielectric layer is 1000˜3000 angstroms in thickness.
Claim 22
Dependent Claim
11 words
The method as claim 13, wherein said dielectric material is polysilicon.
References Cited (Backward Citations)
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