US5468342A
Expired / Lapsed
US
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Method of etching an oxide layer
Assignee: Adeia Semiconductor Technologies LLC
•
Filing: 1994-04-28
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Granted: 1995-11-21
•
Expires: 2014-04-28
Abstract
Abstract A method of etching openings in oxide layers is disclosed. A hard mask layer is formed on the oxide layer. The hard mask layer is then patterned by a photoresist layer and an etch is performed to form openings in the hard mask. Next, the patterning layer may be removed and an etch is performed to remove the oxide in the regions defined by the hard mask layer openings. The etch with hard mask has minimized aspect ratio dependency, so that openings of different sizes may be formed simultaneously. An etch that may be carried out with Freon 134a (C 2 H 2 F 4 ) to provide superior oxide:nitride selectivity is also disclosed. Additionally, the etch may be carried out at high temperature for improved wall profile without loss of selectivity. For deep openings, a two step etch process is disclosed, with a polymer clean step between the etches to remove polymer build up from first etch, and allow the etch to proceed to an increased depth.
Inventors
- 👤 James E. Nulty
- 👤 Pamela S. Trammel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:58
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/73; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/081; H10W20/089; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/945
Claims Analysis
Total Claims: 68
Claim 1
Independent Claim
122 words
A method of etching an oxide layer comprising the steps of: providing a substrate having said oxide layer thereon; depositing a hard mask layer on said oxide layer, wherein said hard mask layer comprises a material selected from the group consisting of silicon nitride, polysilicon, aluminum, a refractory metal, and a refractory metal silicide; forming a patterning layer on said hard mask layer; forming a patterning layer opening in said patterning layer to form a hard mask layer exposed region; forming a hard mask layer opening in said hard mask layer exposed region to form an oxide layer exposed region; and, forming an oxide layer opening in said oxide layer exposed region by exposing said oxide layer exposed region to a plasma.
Claim 2
Independent Claim
122 words
A method of etching an oxide layer comprising the steps of: providing a substrate having said oxide layer thereon; depositing a hard mask layer on said oxide layer, wherein said hard mask layer comprises a material selected from the group consisting of silicon nitride, polysilicon, aluminum, a refractory metal, and a refractory metal silicide; forming a patterning layer on said hard mask layer; forming a patterning layer opening in said patterning layer to form a hard mask layer exposed region; forming a hard mask layer opening in said hard mask layer exposed region to form an oxide layer exposed region; and, forming an oxide layer opening in said oxide layer exposed region by exposing said oxide layer exposed region to a plasma.
Claim 3
Dependent Claim
26 words
The method as described in claim 1 wherein said patterning layer is removed prior to the completion of said step of forming said oxide layer opening.
Claim 4
Dependent Claim
26 words
The method as described in claim 1 wherein said patterning layer is removed prior to the beginning of said step of forming said oxide layer opening.
Claim 5
Dependent Claim
51 words
The method as described in claim 2 wherein a plurality of said patterning layers openings, said hard mask layer openings and said oxide layer openings are formed, and wherein a first one of said oxide layer openings has a different aspect ratio from a second one of said oxide layer openings.
Claim 6
Dependent Claim
32 words
The method as described in claim 1 wherein said substrate is at a temperature of 110° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 7
Dependent Claim
32 words
The method as described in claim 2 wherein said substrate is at a temperature of 110° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 8
Dependent Claim
32 words
The method as described in claim 3 wherein said substrate is at a temperature of 110° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 9
Dependent Claim
32 words
The method as described in claim 1 wherein said substrate is at a temperature of 130° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 10
Dependent Claim
32 words
The method as described in claim 2 wherein said substrate is at a temperature of 130° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 11
Dependent Claim
35 words
The method as described in claim 1 wherein said substrate is at a temperature above a reticulation temperature of said patterning layer during at least some of said step of forming said oxide layer opening.
Claim 12
Dependent Claim
35 words
The method as described in claim 2 wherein said substrate is at a temperature above a reticulation temperature of said patterning layer during at least some of said step of forming said oxide layer opening.
Claim 13
Dependent Claim
19 words
The method as described in claim 1 wherein said substrate comprises a silicon nitride layer underlying said oxide layer.
Claim 14
Dependent Claim
19 words
The method as described in claim 2 wherein said substrate comprises a silicon nitride layer underlying said oxide layer.
Claim 15
Dependent Claim
21 words
The method as described in claim 5 wherein said plasma is formed in a flow comprising CH 2 F--CF 3 .
Claim 16
Dependent Claim
21 words
The method as described in claim 6 wherein said plasma is formed in a flow comprising CH 2 F--CF 3 .
Claim 17
Independent Claim
74 words
A method of etching an oxide layer comprising the steps of: providing a substrate having said oxide layer thereon; forming a masking layer on said Oxide layer, said masking layer being a low carbon content material; forming a masking layer opening in said masking layer to form an oxide layer exposed region; and, forming an oxide layer opening in said oxide layer exposed region by exposing said oxide layer exposed region to a plasma.
Claim 18
Independent Claim
74 words
A method of etching an oxide layer comprising the steps of: providing a substrate having said oxide layer thereon; forming a masking layer on said Oxide layer, said masking layer being a low carbon content material; forming a masking layer opening in said masking layer to form an oxide layer exposed region; and, forming an oxide layer opening in said oxide layer exposed region by exposing said oxide layer exposed region to a plasma.
Claim 19
Dependent Claim
46 words
The method as described in claim 16 wherein a plurality of said masking layer openings and said oxide layer openings are formed, and wherein a first one of said oxide layer openings has a different aspect ratio from a second one of said oxide layer openings.
Claim 20
Dependent Claim
32 words
The method as described in claim 16 wherein said substrate is at a temperature of 110° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 21
Dependent Claim
32 words
The method as described in claim 16 wherein said substrate is at a temperature of 130° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 22
Dependent Claim
21 words
The method as described in claim 16 wherein said plasma is formed in a flow comprising CH 2 F--CF 3 .
Claim 23
Dependent Claim
21 words
The method as described in claim 18 wherein said plasma is formed in a flow comprising CH 2 F--CF 3 .
Claim 24
Independent Claim
78 words
A method of etching an oxide layer comprising the steps of: providing a substrate having said oxide layer thereon; forming a masking layer on said oxide layer; forming a masking layer opening in said masking layer to form an oxide layer exposed region; and, forming an oxide layer opening in said oxide layer exposed region by exposing said oxide layer exposed region to a plasma, wherein said masking layer does not have significant carbon interaction with said plasma.
Claim 25
Independent Claim
78 words
A method of etching an oxide layer comprising the steps of: providing a substrate having said oxide layer thereon; forming a masking layer on said oxide layer; forming a masking layer opening in said masking layer to form an oxide layer exposed region; and, forming an oxide layer opening in said oxide layer exposed region by exposing said oxide layer exposed region to a plasma, wherein said masking layer does not have significant carbon interaction with said plasma.
Claim 26
Dependent Claim
46 words
The method as described in claim 22 wherein a plurality of said masking layer openings and said oxide layer openings are formed, and wherein a first one of said oxide layer openings has a different aspect ratio from a second one of said oxide layer openings.
Claim 27
Dependent Claim
32 words
The method as described in claim 22 wherein said substrate is at a temperature of 110° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 28
Dependent Claim
32 words
The method as described in claim 22 wherein said substrate is at a temperature of 130° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 29
Dependent Claim
21 words
The method as described in claim 22 wherein said plasma is formed in a flow comprising CH 2 F--CF 3 .
Claim 30
Dependent Claim
21 words
The method as described in claim 24 wherein said plasma is formed in a flow comprising CH 2 F--CF 3 .
Claim 31
Independent Claim
65 words
A method of etching an oxide layer comprising the steps of: providing a substrate having said oxide layer thereon; exposing a first portion of said oxide layer and covering a second portion of said oxide layer; and, forming an oxide layer opening in said first portion by exposing said first portion to a plasma formed in a gas flow comprising CH 2 F--CF 3 .
Claim 32
Independent Claim
65 words
A method of etching an oxide layer comprising the steps of: providing a substrate having said oxide layer thereon; exposing a first portion of said oxide layer and covering a second portion of said oxide layer; and, forming an oxide layer opening in said first portion by exposing said first portion to a plasma formed in a gas flow comprising CH 2 F--CF 3 .
Claim 33
Dependent Claim
19 words
The method as described in claim 28 wherein said substrate comprises a silicon nitride layer underlying said oxide layer.
Claim 34
Dependent Claim
73 words
The method as described in claim 28 wherein said step of exposing said first portion and covering said second portion of said oxide layer comprises the steps of: depositing a masking layer on said oxide layer; forming a patterning layer on said masking layer; forming a patterning layer opening in said patterning layer corresponding to said first portion; and, forming a masking layer opening in said masking layer to expose said first portion.
Claim 35
Dependent Claim
73 words
The method as described in claim 29 wherein said step of exposing said first portion and covering said second portion of said oxide layer comprises the steps of: depositing a masking layer on said oxide layer; forming a patterning layer on said masking layer; forming a patterning layer opening in said patterning layer corresponding to said first portion; and, forming a masking layer opening in said masking layer to expose said first portion.
Claim 36
Dependent Claim
26 words
The method as described in claim 29 wherein said patterning layer is removed prior to the completion of said step of forming said oxide layer opening.
Claim 37
Dependent Claim
25 words
The method as described in claim 29 wherein said patterning layer is removed prior to the beginning of-said step of forming said oxide layer opening.
Claim 38
Dependent Claim
50 words
The method as described in claim 31 wherein a plurality of said patterning layers openings, said masking layer openings and said oxide layer openings are formed, and wherein a first one of said oxide layer openings has a different aspect ratio from a second one of said oxide layer openings.
Claim 39
Dependent Claim
30 words
The method as described in claim 28 wherein said masking layer comprises a material selected from the group consisting of polysilicon, aluminum, a refractory metal, and a refractory metal silicide.
Claim 40
Dependent Claim
32 words
The method as described in claim 28 wherein said substrate is at a temperature of 110° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 41
Dependent Claim
32 words
The method as described in claim 28 wherein said substrate is at a temperature of 130° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 42
Dependent Claim
32 words
The method as described in claim 29 wherein said substrate is at a temperature of 110° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 43
Dependent Claim
32 words
The method as described in claim 29 wherein said substrate is at a temperature of 130° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 44
Dependent Claim
32 words
The method as described in claim 31 wherein said substrate is at a temperature of 110° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 45
Dependent Claim
32 words
The method as described in claim 31 wherein said substrate is at a temperature of 130° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 46
Dependent Claim
25 words
The method as described in claim 29 wherein said oxide layer opening exposes a corner of a structure, said corner covered with said nitride layer.
Claim 47
Dependent Claim
25 words
The method as described in claim 31 wherein said oxide layer opening exposes a corner of a structure, said corner covered with said nitride layer.
Claim 48
Dependent Claim
25 words
The method as described in claim 32 wherein said oxide layer opening exposes a corner of a structure, said corner covered with said nitride layer.
Claim 49
Dependent Claim
25 words
The method as described in claim 38 wherein said oxide layer opening exposes a corner of a structure, said corner covered with said nitride layer.
Claim 50
Dependent Claim
25 words
The method as described in claim 39 wherein said oxide layer opening exposes a corner of a structure, said corner covered with said nitride layer.
Claim 51
Dependent Claim
16 words
The method as described in claim 28 wherein said gas flow further comprises CHF 3 .
Claim 52
Dependent Claim
16 words
The method as described in claim 29 wherein said gas flow further comprises CHF 3 .
Claim 53
Dependent Claim
16 words
The method as described in claim 31 wherein said gas flow further comprises CHF 3 .
Claim 54
Dependent Claim
16 words
The method as described in claim 36 wherein said gas flow further comprises CHF 3 .
Claim 55
Dependent Claim
16 words
The method as described in claim 38 wherein said gas flow further comprises CHF 3 .
Claim 56
Dependent Claim
16 words
The method as described in claim 40 wherein said gas flow further comprises CHF 3 .
Claim 57
Independent Claim
95 words
A method of etching an oxide layer comprising the steps of: providing a substrate having said oxide layer thereon; depositing a masking layer on said oxide layer; forming a patterning layer on said masking layer; forming a patterning layer opening in said patterning layer to form a masking layer exposed region; forming a masking layer opening in said masking layer exposed region to form an oxide layer exposed region; exposing said oxide layer exposed region to a first plasma; performing a polymer clean step; and, exposing said oxide layer exposed region to a second plasma.
Claim 58
Independent Claim
95 words
A method of etching an oxide layer comprising the steps of: providing a substrate having said oxide layer thereon; depositing a masking layer on said oxide layer; forming a patterning layer on said masking layer; forming a patterning layer opening in said patterning layer to form a masking layer exposed region; forming a masking layer opening in said masking layer exposed region to form an oxide layer exposed region; exposing said oxide layer exposed region to a first plasma; performing a polymer clean step; and, exposing said oxide layer exposed region to a second plasma.
Claim 59
Dependent Claim
27 words
The method as described in claim 53 wherein said polymer clean step is performed by exposing said substrate to a plasma formed in a mixture comprising oxygen.
Claim 60
Dependent Claim
32 words
The method as described in claim 53 wherein said polymer clean step is performed by exposing said substrate to a mixture comprising H 2 SO 4 and H 2 O 2 .
Claim 61
Dependent Claim
50 words
The method as described in claim 53 wherein a plurality of said patterning layer openings, said masking layer openings, and said oxide layer openings are formed, and wherein a first one of said oxide layer openings has a different aspect ratio from a second one of said oxide layer openings.
Claim 62
Dependent Claim
30 words
The method as described in claim 53 wherein said masking layer comprises a material selected from the group consisting of polysilicon, aluminum, a refractory metal, and a refractory metal silicide.
Claim 63
Dependent Claim
32 words
The method as described in claim 53 wherein said substrate is at a temperature of 110° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 64
Dependent Claim
32 words
The method as described in claim 53 wherein said substrate is at a temperature of 130° C. or greater during at least some of said step of forming said oxide layer opening.
Claim 65
Dependent Claim
23 words
The method as described in claim 53 wherein said second plasma is formed in a gas flow comprising CH 2 F--CF 3 .
Claim 66
Dependent Claim
23 words
The method as described in claim 57 wherein said second plasma is formed in a gas flow comprising CH 2 F--CF 3 .
Claim 67
Dependent Claim
23 words
The method as described in claim 58 wherein said second plasma is formed in a gas flow comprising CH 2 F--CF 3 .
Claim 68
Dependent Claim
23 words
The method as described in claim 59 wherein said second plasma is formed in a gas flow comprising CH 2 F--CF 3 .
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| 3.5 Years (Year 4) | 1998-11-20 | 1999-05-22 | 1999-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-11-20 | 2003-05-22 | 2003-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-11-20 | 2007-05-22 | 2007-11-21 | $7700.00 | Window Closed / Lapsed |