US5911110A
Expired / Lapsed
US
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Method of forming shallow trench isolation with dummy pattern in reverse tone mask
Assignee: Taiwan Semiconductor Manufacturing Co TSMC Ltd
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Filing: 1997-10-28
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Granted: 1999-06-08
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Expires: 2017-10-28
Abstract
Abstract A thin silicon dioxide layer and a silicon nitride layer are respectively formed on a wafer. A plurality of shallow trenches are formed in the wafer. A trench filling layer is successively refilled into the trenches for isolation. A reverse tone mask with a dummy pattern mask is patterned on top of the trench filling material. An etching is performed to etch the trench filling material using the reverse tone mask and the dummy pattern mask as etching masks. The reverse tone mask and the dummy pattern mask are then stripped away. A chemical mechanical polishing (CMP) technology is used to remove the trench filling layer to the surface of the silicon nitride layer for planarization.
Inventors
- 👤 Chen-Hua Yu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:17
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: 17
Claim 1
Independent Claim
131 words
A method of forming a trench isolation on a silicon wafer, said method comprising the following steps of: forming a pad layer on said silicon wafer; forming a silicon nitride layer over said pad layer; forming a plurality of trenches in said silicon wafer by etching said silicon nitride layer, said pad layer and said silicon wafer, after said plurality of trenches are formed, said silicon wafer including a first area not including said plurality of trenches, and a second area including said plurality of trenches; forming a trench filling layer for isolation on said silicon nitride layer and filling into said plurality of trenches; and patterning said trench filling layer to form a dummy pattern including a plurality of protruding portions on at least a portion of said first area.
Claim 2
Independent Claim
131 words
A method of forming a trench isolation on a silicon wafer, said method comprising the following steps of: forming a pad layer on said silicon wafer; forming a silicon nitride layer over said pad layer; forming a plurality of trenches in said silicon wafer by etching said silicon nitride layer, said pad layer and said silicon wafer, after said plurality of trenches are formed, said silicon wafer including a first area not including said plurality of trenches, and a second area including said plurality of trenches; forming a trench filling layer for isolation on said silicon nitride layer and filling into said plurality of trenches; and patterning said trench filling layer to form a dummy pattern including a plurality of protruding portions on at least a portion of said first area.
Claim 3
Dependent Claim
29 words
The method of claim 1 further comprising the step of: after the step of patterning said trench filling layer, planarizing said trench filling layer by using chemical mechanical polishing.
Claim 4
Dependent Claim
25 words
The method of claim 1 further comprising the step of: after the step of forming said trench filling layer, performing a thermal annealing for densification.
Claim 5
Dependent Claim
25 words
The method of claim 2 further comprising the step of: after the step of forming said trench filling layer, performing a thermal annealing for densification.
Claim 6
Dependent Claim
53 words
The method of claim 1, wherein the step of forming said plurality of trenches comprises: patterning a photoresist on said silicon nitride layer to define a plurality of trench regions; etching said silicon nitride layer, said pad layer and said silicon wafer by using said photoresist as a mask; and removing said photoresist.
Claim 7
Dependent Claim
42 words
The method of claim 1, wherein said dummy pattern covers a first portion of said trench filling layer and exposes a second portion of said trench filling layer, a width of said first portion being close to a width of said trench.
Claim 8
Dependent Claim
32 words
The method of claim 1, wherein said trench filling layer is selected from the group consisting of PE-oxide (plasma enhanced oxide) layer, SACVD-oxide (sub-atmospheric chemical vapor deposition oxide) layer and ozone-TEOS layer.
Claim 9
Dependent Claim
23 words
The method of claim 6, wherein said ozone-TEOS layer is formed at a temperature in the range of about 400 to 480° C.
Claim 10
Dependent Claim
41 words
The method of claim 1, wherein said silicon nitride layer is formed by a method selected from the group consisting of Low Pressure Chemical Vapor Deposition (LPCVD), Plasma Enhanced Chemical Vapor Deposition (PECVD) and High Density Plasma Chemical Vapor Deposition (HDPCVD).
Claim 11
Dependent Claim
28 words
The method of claim 9, wherein the reaction gases of forming said silicon nitride layer comprises SiH 4 , NH 3 , N 2 , N 2 O.
Claim 12
Dependent Claim
30 words
The method of claim 9, wherein the reaction gases of forming said silicon nitride layer comprises SiH 2 Cl 2 , NH 3 , N 2 , N 2 O.
Claim 13
Dependent Claim
18 words
The method of claim 9, wherein the temperature of forming said silicon nitride layer is about 400-800° C.
Claim 14
Dependent Claim
21 words
The method of claim 3, wherein said thermal annealing is carried out at a temperature of about 950 to 1050° C.
Claim 15
Dependent Claim
18 words
The method of claim 13, wherein said thermal annealing is carried out for about 30 to 130 minutes.
Claim 16
Dependent Claim
21 words
The method of claim 4, wherein said thermal annealing is carried out at a temperature of about 950 to 1050° C.
Claim 17
Dependent Claim
18 words
The method of claim 15, wherein said thermal annealing is carried for out about 30 to 130 minutes.
References Cited (Backward Citations)
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