MANUFACTURE OF SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To prevent the formation of an unetched pattern by completely and quickly removing a natural oxide film formed on a polycrystalline silicon film even near a step. SOLUTION: When a polycrystalline silicon film 3 is formed on a base film on which steps are formed due to a silicon...

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Bibliographic Details
Main Author AKASHI KEISUKE
Format Patent
LanguageEnglish
Published 18.02.1997
Edition6
Subjects
BASIC ELECTRIC ELEMENTS
ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
ELECTRICITY
SEMICONDUCTOR DEVICES
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Summary:PROBLEM TO BE SOLVED: To prevent the formation of an unetched pattern by completely and quickly removing a natural oxide film formed on a polycrystalline silicon film even near a step. SOLUTION: When a polycrystalline silicon film 3 is formed on a base film on which steps are formed due to a silicon oxide film 2, a natural oxide film 4 is formed on the silicon film 3. The natural oxide film 4 is removed by dry- etching the film 4 with the plasma of a CF4 gas by using a photoresist 5 as a mask. Since the selection ratio of etching using the CF4 between a polycrystalline silicon film and a silicon oxide film is very small, the natural oxide film 4 can be removed completely and quickly without excessively etching the polycrystalline silicon film 3 even when the film 4 has a very large effective film thickness in the vertical direction and the film 4 exists near a step. Then the film 3 is successively removed by dry etching using the plasma of an HBr gas.
Bibliography:Application Number: JP19950219599