Title:
FORMATION OF CONTACT HOLE
Document Type and Number:
Japanese Patent JPS574122
Kind Code:
A
Abstract:
PURPOSE:To obtain the contact hole without sagging by a method wherein a PSG film and an Si3N4 film are laminated and coated on the surface of a semiconductor substrate, an aperture is provided oh the PSG film, the exposed part of the Si3N4 film is thinned by etching and after an etching is performed on the aperture section of the PSG film in lateral direction, the thinned part of the Si3N4 film is removed. CONSTITUTION:The PSG film 21 and the Si3N4 film 22 are laminated and coated on the semiconductor substrate 20 and a photomask 24 having a contact hole 23 is provided on the surface of said coating. Then, using a thermal phosphate, a hole 23 is provided on the film 22, and then the thickness of the film 21 exposed on the inner surface of the hole 23 is thinned using a hydrofluoric enchant. Then, the diameter of the hole 23 on the film 22 is widened and a stepped section 25 is created by overetching a CF4 plasma in lateral direction, the mask 24 is removed, the exposed thin film 21 is removed with a hydrofluoric solution using the remaining film 22 as a mask and the substrate 20 is exposed. Through these procedures, the contact hole having no sagging at the edge can be obtained.
Inventors:
YOSHINO HIROTETSU
Application Number:
JP7806180A
Publication Date:
January 09, 1982
Filing Date:
June 09, 1980
Export Citation:
Assignee:
SANYO ELECTRIC CO
International Classes:
H01L21/3205; H01L21/28; H01L21/306; (IPC1-7): H01L21/306; H01L21/88
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