| 摘要 |
PURPOSE:To improve reliability by tapering an opening section in a photo-resist through plasma etching treating previously using a mixed gas containing a chlorine compound and forming a contact hole with a taper having excellent reproducibility to an insulating film. CONSTITUTION:A photo-resist film 3 is shaped onto an insulating film such as a phosphorus silicate glass film 2 formed onto an silicon substrate 1, and an opening section 4 is shaped. The thickness of the photo-resist film 3 is brought to approximately three quarters or half of initial film thickness through plasma etching by employing a gas containing a chlorine compound such as a mixed gas containing at least carbon tetrachloride and boron trichloride. The photo-resist film 3 is thinned through the treatment while a taper having an inclination of approximately 70 deg.-85 deg. is shaped to the side wall 5 of the opening section 4. The width W1 of the opening section in the photo-resist is made wider than an initial value W by approximately ten %. The phosphorus silicate glass film 2 is plasma-etched by the mixed gas of CHF3 and O2 to form a contact hole 6, and the width W2 of the contact hole 6 is made wider than that W of the opening section 4 in the photo-resist by approximately ten %.
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