EP0516043A2
Expired / Lapsed
EP
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Dry etching method
Assignee: Tokyo Electron Ltd
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Filing: 1992-05-26
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Granted: —
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Expires: 2012-05-26
Abstract
Abstract A dry etching method, wherein a multilayer film including one selected from tungsten, molybdenum, and a silicide thereof, as the first layer, and polycrystal silicon as the second layer underlying is formed on a silicon oxide insulation film, a substrate having a mask pattern on the multilayer film is placed in a vacuum container, an etching gas is introduced into the vacuum container, and an electrical discharge is induced by applying an electrical field to the vacuum container, thereby anisotropically etching the multilayered film in accordance with the mask pattern. The method comprises the first etching step for etching the first layer by use of the first gas selected from fluorine, sulfur hexafluoride, and nitrogen trifluoride, or a mixture gas containing the first gas and the second gas selected from hydrogen chloride, hydrogen bromide, chlorine, bromine, and carbon tetrachloride, as an etching gas, and the second etching step for etching the second layer by use of the second gas, or a mixture gas containing the second gas and the third gas selected from an inert gas, nitrogen gas, oxygen gas, silicon tetrachloride gas and carbon monoxide gas, as an etching gas.
Inventors
- 👤 Masaru C/O Intellectual Property Division Hori
- 👤 Keiji c/o Intellectual Property Division Horioka
- 👤 Haruo c/o Intellectual Property Division Okano
- 👤 Masao c/o Intellectual Property Division Ito
- 👤 Masahito c/o Operat. Head Office Tokyo Hiratsuka
- 👤 Yoshio c/o Operat. Head Office Tokyo Ishikawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 09:52
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
217 words
A dry etching method, wherein a multilayer film including one selected from the group consisting of tungsten, molybdenum, a tungsten silicide, and a molybdenum silicide, as the first layer, and polycrystal silicon as the second layer underlying is formed on a silicon oxide insulation film, a processed substrate prepared by forming a mask pattern on the multilayer film is placed in a vacuum container, an etching gas is introduced into the vacuum container, and an electrical discharge is induced by applying an electrical field to the vacuum container, thereby anisotropically etching the multilayered film in accordance with the mask pattern, comprising: the first etching step for etching the first layer by use of the first gas which is selected from the group consisting of fluorine, sulfur hexafluoride, and nitrogen trifluoride, or a mixture gas containing the first gas and the second gas which is selected from the group consisting of hydrogen chloride, hydrogen bromide, chlorine, bromine, and carbon tetrachloride, as an etching gas; and the second etching step for etching the second layer by use of the second gas, or a mixture gas containing the second gas and the third gas which is selected from the group consisting of an inert gas, nitrogen gas, oxygen gas, silicon tetrachloride gas and carbon monoxide gas, as an etching gas.
Claim 2
Dependent Claim
67 words
A dry etching method according to claim 1, characterized in that in the first etching step, a mixture gas containing chlorine and sulfur hexafluoride at a mixture ratio of 4 : 6 to 7 : 3, is used as the etching gas, and a gas flow amount, and a high frequency power density are set to 20-150 sccm, and 0.4-0.9 W/cm², respectively, to etch the first layer.
Claim 3
Dependent Claim
61 words
A dry etching method according to claim 1, characterized in that in the second etching step, an amount of the third gas which is selected from the group consisting of an inert gas, nitrogen gas, oxygen gas, silicon tetrachloride gas and carbon monoxide gas, and mixed into the second gas is 0-10 volume% of the whole amount of the etching gas.
Claim 4
Dependent Claim
61 words
A dry etching method according to claim 1, characterized in that in the first etching step, the third gas which is selected from the group consisting of inert gas, nitrogen gas, oxygen gas, silicon tetrachloride gas, and carbon monoxide gas, is further added to the etching gas in an amount of 0-10 volume% of the whole amount of the etching gas.
Claim 5
Dependent Claim
36 words
A dry etching method according to claim 1, characterized in that the first and second etching steps are carried out while maintaining the temperature of the to-be-processed substrate in the range between -10 and - 120°C.
Claim 6
Dependent Claim
35 words
A dry etching method according to claim 1, characterized in that the first and second etching steps are carried out while maintaining the temperature of the to-be-processed substrate in the range between -30 and -60°C.
Claim 7
Dependent Claim
27 words
A dry etching method according to claim 1, characterized in that the first etching step is carried out while detecting an end point of etching by monitor.
Claim 8
Dependent Claim
27 words
A dry etching method according to claim 1, characterized in that the second etching step is carried out while detecting an end point of etching by monitor.
Claim 9
Dependent Claim
28 words
A dry etching method according to claim 1, characterized in that even after etching the first layer, the etching may be continued to etch the underlying polycrystal silicon.
Claim 10
Dependent Claim
33 words
A dry etching method according to claim 1, characterized in that the first and second etching steps are performed by a reactive ion etching device of a magnetron type or discharge plasma type.
Claim 11
Dependent Claim
25 words
A dry etching method according to claim 1, characterized in that the first and second etching steps are performed by a plasma type etching device.
Claim 12
Dependent Claim
221 words
A dry etching method, wherein a thin film including a metal or metal compound selected from the group consisting of tungsten, molybdenum, a tungsten silicide, and a molybdenum silicide, is formed as a first layer on a silicon oxide insulation film, a to-be-processed substrate prepared by forming a mask pattern on the thin film is placed in a vacuum container, an etching gas is introduced into the vacuum container, and an electrical discharge is induced by applying an electrical field to the vacuum container, thereby anisotropically etching the thin film in accordance with the mask pattern, characterized in that the first layer is etched while maintaining the temperature of the to-be-processed substrate in the range between -10 and -120°C, by use of: the first gas which is selected from the group consisting of fluorine, sulfur hexafluoride, and nitrogen trifluoride; or a mixture gas containing the first gas and the second gas which is selected from the group consisting of hydrogen chloride, hydrogen bromide, chlorine, bromine, and carbon tetrachloride; or a mixture gas containing the first and second gases, and the third gas which is selected from the group consisting of an inert gas, nitrogen gas, oxygen gas, silicon tetrachloride gas and carbon monoxide gas; and or a mixture gas containing the first gas and the third gas, as an etching gas.
References Cited (Backward Citations)
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