US5057187A
Expired / Lapsed
US
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Ashing method for removing an organic film on a substance of a semiconductor device under fabrication
Assignee: Fujitsu Ltd
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Filing: 1990-05-18
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Granted: 1991-10-15
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Expires: 2010-05-18
Abstract
Abstract Plasma ashing methods, for moving a resist material formed on a ground layer of a semiconductor device during fabrication of said semiconductor, are performed by using one of three kinds of reactant gases each composed of three different gases. Plasma ashing is performed: at an ashing rate of 0.5 μm/min at 160° C. and with an activation energy of 0.4 eV when a reactant gas composed of oxygen, water vapor and nitrogen is used; at an ashing rate of 0.5 μm/min at 140° C., with an activation energy of 0.38 eV and without etching the ground layer when a reactant gas composed of oxygen, water vapor and tetrafluoromethane is used; and at an ashing rate of 0.5 μm/min at 140° C., with an activation energy of 0.4 eV when a reactant gas composed of oxygen, hydrogen and nitrogen is used.
Inventors
- 👤 Keisuke Shinagawa
- 👤 Shuzo Fujimura
- 👤 Kenichi Hikazutani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:23
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/286; H10P50/287; G; G03; G03F; G03F7/00; G03F7/26; G03F7/42; G03F7/427
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
177 words
A method for removing an organic material formed on a ground substance of a semiconductor device, which comprises the steps of: providing as a reactant gas, a mixed gas comprising oxygen, hydrogen, which comprises more than 1% of the mixed gas, and an additional gas; controlling ratios of oxygen, hydrogen and said additional gas in said mixed gas such that when said reactant gas is formed into a plasma, and said plasma is impinged on said organic material under ashing conditions, the ashing rate is larger than and the activation energy is at most equal to, those respectively which would be achieved by using a reactant gas composed of oxygen and hydrogen; generating a first plasma of said reactant gas; providing a second plasma down stream of said first plasma, whereby producing active species of said reactant gas; and impinging said second plasma on said organic material down stream from said first plasma generating step, whereby removing the orgnaic material by means of the active species of said second plasma, but leaving the ground substance substantially unremoved.
Claim 2
Independent Claim
177 words
A method for removing an organic material formed on a ground substance of a semiconductor device, which comprises the steps of: providing as a reactant gas, a mixed gas comprising oxygen, hydrogen, which comprises more than 1% of the mixed gas, and an additional gas; controlling ratios of oxygen, hydrogen and said additional gas in said mixed gas such that when said reactant gas is formed into a plasma, and said plasma is impinged on said organic material under ashing conditions, the ashing rate is larger than and the activation energy is at most equal to, those respectively which would be achieved by using a reactant gas composed of oxygen and hydrogen; generating a first plasma of said reactant gas; providing a second plasma down stream of said first plasma, whereby producing active species of said reactant gas; and impinging said second plasma on said organic material down stream from said first plasma generating step, whereby removing the orgnaic material by means of the active species of said second plasma, but leaving the ground substance substantially unremoved.
Claim 3
Dependent Claim
21 words
A method according to claim 1, wherein said organic material removing step is performed down stream from said plasma generating step.
Claim 4
Dependent Claim
21 words
A method according to claim 1, wherein said additional gas is selected from the group consisting of nitrogen and nitrogen oxide.
Claim 5
Dependent Claim
52 words
A method according to claim 3, wherein the additional gas is nitrogen, and wherein the ratios of oxygen, hydrogen, and nitrogen are selected such that hydrogen is more than 3% of the sum of hydrogen and nitrogen, and nitrogen is more than 5% of the sum of the oxygen and the nitrogen.
Claim 6
Dependent Claim
29 words
A method according to claim 4, wherein the temperature of the organic material is higher than 140° C., so as to obtain an ashing rate higher than 0.5 μm/min.
Claim 7
Independent Claim
147 words
A method for removing an organic material formed on a ground substance of a semiconductor device, comprising the steps of: providing a mixed reactant gas consisting essentially of oxygen, hydrogen and an additional gas; controlling the ratios of oxygen, hydrogen and the additional gas of said mixed gas to obtain a reactant gas sufficient to perform plasma ashing at an ashing rate higher than, and with an activation energy at most equal to, those obtainable, respectively, where the reactant gas is composed of oxygen and hydrogen, and without etching the ground substance; generating a first plasma of said reactant gas; providing a second plasma down stream of said first plasma, whereby producing active species of said reactant gas; and removing said organic material by impinging said active species in said second plasma thereon down stream from said first plasma generating step, without substantially etching the ground substance.
Claim 8
Independent Claim
147 words
A method for removing an organic material formed on a ground substance of a semiconductor device, comprising the steps of: providing a mixed reactant gas consisting essentially of oxygen, hydrogen and an additional gas; controlling the ratios of oxygen, hydrogen and the additional gas of said mixed gas to obtain a reactant gas sufficient to perform plasma ashing at an ashing rate higher than, and with an activation energy at most equal to, those obtainable, respectively, where the reactant gas is composed of oxygen and hydrogen, and without etching the ground substance; generating a first plasma of said reactant gas; providing a second plasma down stream of said first plasma, whereby producing active species of said reactant gas; and removing said organic material by impinging said active species in said second plasma thereon down stream from said first plasma generating step, without substantially etching the ground substance.
Claim 9
Dependent Claim
19 words
A method according to claim 6, wherein said removing step is performed down stream from said plasma generating step.
Claim 10
Dependent Claim
25 words
A method according to claim 7, wherein said additional gas is selected from a halogenide group consisting of tetrafluoromethane, chlorine, nitrogen trifluoride, hexafluoroethane and trifluoromethane.
References Cited (Backward Citations)
US4689112A
Cited
US4673456A
Cited
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