Patent US5985735A successfully refreshed from Google Patents.
US5985735A
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Trench isolation process using nitrogen preconditioning to reduce crystal defects
Assignee: Intel Corp
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Filing: 1995-09-29
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Granted: 1999-11-16
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Expires: 2015-09-29
Abstract
Abstract A method of forming a trench isolation structure in a semiconductor substrate. After etching a trench into the semiconductor substrate, an oxide layer is formed within the trench. The surface of this oxide layer is subjected to a nitrogen plasma. Subsequently, another oxide layer is deposited over the nitrogen-rich surface of the first oxide layer. Deposition of this second oxide layer is accomplished by a chemical vapor deposition (CVD) process primarily using a reactant gas other than ozone.
Inventors
- 👤 Peter K. Moon
- 👤 David T. Krick
- 👤 Kerry L. Spurgin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:31
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: 17
Claim 1
Independent Claim
81 words
A method of forming an isolation structure in a semiconductor substrate comprising the steps of: a) etching a trench in the semiconductor substrate; b) forming a first oxide layer within the trench; c) subjecting a surface of the first oxide layer to a nitrogen plasma; and d) depositing a second oxide layer on the surface of the first oxide layer, the second oxide layer being deposited by a chemical vapor deposition (CVD) process primarily using a reactant gas other than ozone.
Claim 2
Independent Claim
81 words
A method of forming an isolation structure in a semiconductor substrate comprising the steps of: a) etching a trench in the semiconductor substrate; b) forming a first oxide layer within the trench; c) subjecting a surface of the first oxide layer to a nitrogen plasma; and d) depositing a second oxide layer on the surface of the first oxide layer, the second oxide layer being deposited by a chemical vapor deposition (CVD) process primarily using a reactant gas other than ozone.
Claim 3
Dependent Claim
28 words
The method of claim 1 further comprising the step of performing a chemical mechanical polishing etch-back step to isolate the first and second oxide layers within the trench.
Claim 4
Dependent Claim
23 words
The method of claim 1 wherein the first oxide layer is formed by a method including growing a thermal oxide within the trench.
Claim 5
Dependent Claim
18 words
The method of claim 1 wherein the second oxide layer is deposited by a plasma-enhanced CVD (PECVD) process.
Claim 6
Dependent Claim
16 words
The method of claim 4 wherein the second oxide layer is a substantially undoped oxide layer.
Claim 7
Dependent Claim
33 words
The method of claim 1 wherein the second oxide layer is a doped oxide selected from a group consisting of borosilicate glass (BSG), phosphosilicate glass (PSG), borophosphosilicate glass (BPSG), and any combination thereof.
Claim 8
Dependent Claim
15 words
The method of claim 4 wherein the PECVD process is performed using a TEOS chemistry.
Claim 9
Dependent Claim
19 words
The method of claim 1 wherein the second oxide layer is deposited by a low pressure CVD (LPCVD) process.
Claim 10
Dependent Claim
24 words
The method of claim 3 wherein the nitrogen plasma creates a nitrogen-rich surface of the first oxide layer that is approximately one monolayer thick.
Claim 11
Independent Claim
110 words
A method of forming an isolation structure in a semiconductor substrate comprising the steps of: a) etching a trench in the semiconductor substrate; b) growing a thermal oxide within the trench to form a first oxide layer; c) subjecting the first oxide layer to a nitrogen plasma to form a nitrogen-rich surface on the first oxide layer; d) depositing a second oxide layer over the nitrogen-rich surface of the first oxide layer, the second oxide layer being deposited by a chemical vapor deposition (CVD) process in the absence of ozone; and e) performing a chemical mechanical polishing etch-back step to isolate the first and second oxide layers within the trench.
Claim 12
Independent Claim
110 words
A method of forming an isolation structure in a semiconductor substrate comprising the steps of: a) etching a trench in the semiconductor substrate; b) growing a thermal oxide within the trench to form a first oxide layer; c) subjecting the first oxide layer to a nitrogen plasma to form a nitrogen-rich surface on the first oxide layer; d) depositing a second oxide layer over the nitrogen-rich surface of the first oxide layer, the second oxide layer being deposited by a chemical vapor deposition (CVD) process in the absence of ozone; and e) performing a chemical mechanical polishing etch-back step to isolate the first and second oxide layers within the trench.
Claim 13
Dependent Claim
19 words
The method of claim 10 wherein the nitrogen-rich surface of the first oxide layer is approximately one monolayer thick.
Claim 14
Dependent Claim
16 words
The method of claim 10 wherein the second oxide layer is a substantially undoped oxide layer.
Claim 15
Dependent Claim
33 words
The method of claim 10 wherein the second oxide layer is a doped oxide selected from a group consisting of borosilicate glass (BSG), phosphosilicate glass (PSG), borophosphosilicate glass (BPSG), and any combination thereof.
Claim 16
Dependent Claim
20 words
The method of claim 10 wherein the CVD process is a plasma-enhanced CVD (PECVD) process performed using a TEOS chemistry.
Claim 17
Dependent Claim
21 words
The method of claim 10 wherein the CVD process is a low pressure CVD (LPCVD) process performed using a TEOS chemistry.
References Cited (Backward Citations)
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