Patent US5866483A successfully refreshed from Google Patents.
US5866483A
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Method for anisotropically etching tungsten using SF6, CHF3, and N2
Assignee: Applied Materials Inc
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Filing: 1997-04-04
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Granted: 1999-02-02
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Expires: 2017-04-04
Abstract
Abstract A method for etching a tungsten containing layer 25 on a substrate 10 substantially anisotropically, with good etching selectivity, and without forming excessive passivating deposits on the etched features. In the method, the substrate 10 is placed in a plasma zone 55, and process gas comprising SF6, CHF3, and N2, is introduced into the plasma zone. A plasma is formed from the process gas to anisotropically etch the tungsten containing layer 22. Preferably, the plasma is formed using combined inductive and capacitive plasma operated at a predefined inductive:capacitive power ratio.
Inventors
- 👤 Guang-Jye Shiau
- 👤 Paul Herz
- 👤 Xian-Can Deng
- 👤 Xiaobing Diana Ma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:03
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/242; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10W; H10W20/00; H10W20/01; H10W20/031
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
77 words
A method of anisotropically etching a tungsten containing layer on a substrate, the method comprising the steps of: (a) placing the substrate in a plasma zone; (b) introducing into the plasma zone, a process gas comprising SF 6 , CHF 3 , and N 2 ; and (c) forming a plasma from the process gas to etch the tungsten containing layer on the substrate (i) substantially anisotropically, and (ii) without forming excessive passivating deposits on the substrate.
Claim 2
Independent Claim
77 words
A method of anisotropically etching a tungsten containing layer on a substrate, the method comprising the steps of: (a) placing the substrate in a plasma zone; (b) introducing into the plasma zone, a process gas comprising SF 6 , CHF 3 , and N 2 ; and (c) forming a plasma from the process gas to etch the tungsten containing layer on the substrate (i) substantially anisotropically, and (ii) without forming excessive passivating deposits on the substrate.
Claim 3
Dependent Claim
50 words
The method of claim 1, wherein the volumetric flow ratio of SF 6 :CHF 3 :N 2 is selected to provide etched features having (i) a critical dimension loss of less than 4%, and (ii) sidewalls that form angles of at least about 88° with a surface of the substrate.
Claim 4
Dependent Claim
24 words
The method of claim 1, wherein the volumetric flow ratio of SF 6 :CHF 3 :N 2 is from about 1:1:1 to about 8:1:1.
Claim 5
Dependent Claim
24 words
The method of claim 3, wherein the volumetric flow ratio of SF 6 :CHF 3 :N 2 is from about 2:1:1 to about 5:1:1.
Claim 6
Dependent Claim
22 words
The method of claim 1, wherein the process gas consists essentially of SF 6 , CHF 3 , and N 2 .
Claim 7
Dependent Claim
58 words
The method of claim 1, wherein in step (c), the plasma is formed by applying a current at a power level of about 200 to 2000 Watts to an inductor coil adjacent to the plasma zone, and by applying a voltage at a power level of about 5 to 500 Watts to process electrodes in the plasma zone.
Claim 8
Independent Claim
140 words
A method of etching a substrate comprising a tungsten containing layer, the method comprising the steps of: (a) placing the substrate in a process chamber comprising (i) process electrodes therein, and (ii) an inductor coil adjacent to the process chamber; (b) introducing into the process chamber, process gas comprising SF 6 , CHF 3 , and N 2 ; and (c) ionizing the process gas to form plasma ions that energetically impinge on the substrate by (i) applying RF current at a first power level to the inductor coil, and (ii) applying RF voltage at a second power level to the process electrodes, wherein a power ratio P r of the first power level to the second power level is selected so that the tungsten containing layer is substantially anisotropically etched without excessive deposition of passivating material on the substrate.
Claim 9
Independent Claim
140 words
A method of etching a substrate comprising a tungsten containing layer, the method comprising the steps of: (a) placing the substrate in a process chamber comprising (i) process electrodes therein, and (ii) an inductor coil adjacent to the process chamber; (b) introducing into the process chamber, process gas comprising SF 6 , CHF 3 , and N 2 ; and (c) ionizing the process gas to form plasma ions that energetically impinge on the substrate by (i) applying RF current at a first power level to the inductor coil, and (ii) applying RF voltage at a second power level to the process electrodes, wherein a power ratio P r of the first power level to the second power level is selected so that the tungsten containing layer is substantially anisotropically etched without excessive deposition of passivating material on the substrate.
Claim 10
Dependent Claim
66 words
The method of claim 7, wherein the power ratio P r of the first power level to the second power level and the volumetric flow ratio of SF 6 :CHF 3 :N 2 is selected to provide etched features having (i) a critical dimension loss of less than 4%, and (ii) sidewalls that form angles of at least about 88° with a surface of the substrate.
Claim 11
Dependent Claim
26 words
The method of claim 7, wherein the power ratio P r of the first power level to the second power level is at least about 4:1.
Claim 12
Dependent Claim
28 words
The method of claim 9, wherein the power ratio P r of the first power level to the second power level is from about 8:1 to about 40:1.
Claim 13
Dependent Claim
18 words
The method of claim 7, wherein the first power level is from about 200 to about 2000 Watts.
Claim 14
Dependent Claim
17 words
The method of claim 7, wherein the second power level is about 5 to about 500 Watts.
Claim 15
Dependent Claim
24 words
The method of claim 7, wherein the volumetric flow ratio of SF 6 :CHF 3 :N 2 is from about 1:1:1 to about 8:1:1.
Claim 16
Dependent Claim
24 words
The method of claim 13, wherein the volumetric flow ratio of SF 6 :CHF 3 :N 2 is from about 2:1:1 to about 5:1:1.
Claim 17
Dependent Claim
22 words
The method of claim 7, wherein the process gas consists essentially of SF 6 , CHF 3 , and N 2 .
Claim 18
Independent Claim
151 words
A method of etching a substrate comprising a tungsten containing layer, the method comprising the steps of: (a) placing the substrate in a process chamber comprising (i) process electrodes therein, and (ii) an inductor coil adjacent to the process chamber; (b) introducing into the process chamber, process gas comprising SF 6 , CHF 3 , and N 2 in a volumetric flow ratio of from about 1:1:1 to about 8:1:1; and (c) ionizing the process gas to form plasma ions that energetically impinge on the substrate by (i) applying RF current at a first power level to the inductor coil, and (ii) applying RF voltage at a second power level to the process electrodes, wherein a power ratio P r of the first power level to the second power level is selected so that the tungsten containing layer is substantially anisotropically etched without excessive deposition of passivating material on the substrate.
Claim 19
Independent Claim
151 words
A method of etching a substrate comprising a tungsten containing layer, the method comprising the steps of: (a) placing the substrate in a process chamber comprising (i) process electrodes therein, and (ii) an inductor coil adjacent to the process chamber; (b) introducing into the process chamber, process gas comprising SF 6 , CHF 3 , and N 2 in a volumetric flow ratio of from about 1:1:1 to about 8:1:1; and (c) ionizing the process gas to form plasma ions that energetically impinge on the substrate by (i) applying RF current at a first power level to the inductor coil, and (ii) applying RF voltage at a second power level to the process electrodes, wherein a power ratio P r of the first power level to the second power level is selected so that the tungsten containing layer is substantially anisotropically etched without excessive deposition of passivating material on the substrate.
Claim 20
Dependent Claim
54 words
The method of claim 16, wherein the power ratio P r of the first power level to the second power level is selected to provide etched features having (i) a critical dimension loss of less than 4%, and (ii) sidewalls that form angles of at least about 88° with a surface of the substrate.
Claim 21
Dependent Claim
26 words
The method of claim 16, wherein the power ratio P r of the first power level to the second power level is at least about 4:1.
Claim 22
Dependent Claim
28 words
The method of claim 16, wherein the power ratio P r of the first power level to the second power level is from about 8:1 to about 40:1.
Claim 23
Dependent Claim
18 words
The method of claim 16, wherein the first power level is from about 200 to about 2000 Watts.
Claim 24
Dependent Claim
17 words
The method of claim 16, wherein the second power level is about 5 to about 500 Watts.
Claim 25
Dependent Claim
24 words
The method of claim 16, wherein the volumetric flow ratio of SF 6 :CHF 3 :N 2 is from about 2:1:1 to about 5:1:1.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2002-02-01 | 2002-08-03 | 2003-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-02-01 | 2006-08-03 | 2007-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-02-01 | 2010-08-03 | 2011-02-02 | $7700.00 | Window Closed / Lapsed |