Title:
FORMATION OF VERY FINE APERTURE IN SILICON NITRIDE FILM
Document Type and Number:
Japanese Patent JPS5771136
Kind Code:
A
Abstract:
PURPOSE:To create a very fine aperture in an Si3N4 film by a method wherein a photoresist mask is used to selectively convert into SiO2 the polycrystalline Si film layed on an si3N4 film and then the resultant SiO2 serves as a mask. CONSTITUTION:Films of Si3N4 2, polycrystalline Si 3, Si3N4 4, SiO2 5 are piled one upon another on an Si substrate 1 by means of the CVD techinique. A photoresist mask 6 is then applied and a pattern 15 is formed by selectively etching the SiO2 film 5 using HF solution. The Si3N4 film 4 is selectively etched by hot phosphoric acid with the pattern 15 serving as mask. The mask 15 is removed and a pattern 14 is formed of Si3N4. Next, using the pattern 14 as mask, the polycrystalline Si film 3 is selectively changed into an SiO2 film 23 in a wet oxidating environment. The period of heat treatment is regulated to control the side-wise growth of SiO2 from the pattern 14, thereby determining the width of the remaining portion of the polycrystalline Si film 13. The mask 14 is removed and the polycrystalline Si film 13 is etched away, and then the Si3N4 film 2 is etched away with the film 23 as mask, leaving behind a very fine aperture 7. Then the mask 23 is removed, completing the process.
Inventors:
SAKAMOTO TOSHIROU
Application Number:
JP14684980A
Publication Date:
May 01, 1982
Filing Date:
October 22, 1980
Export Citation:
Assignee:
TOKYO SHIBAURA ELECTRIC CO
International Classes:
H01L21/306; H01L21/033; (IPC1-7): H01L21/306