JPS55105332A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE: To make the opening area accurate and to obtain high density in forming an opening hole in an Si₃N₄ layer on a semiconductor layer by introducing P impurities in the layer on which opening hole is formed and making the layer to become PSG, thereafter removing it by using acidic solution.

CONSTITUTION: A thick field oxide film 34 is formed on the peripheral portion of a p-type Si substrate 31 via a p-type channel stopper region 32; a thin gate oxide film 30 is deposited on the substrate 31 surrounded by a film 34; and an n-type polycrystal lene layer 35, an Si₃N₄ layer 36, and an Si₂O₃ layer 37 are laminated and grown on the plane including the portions mentioned above. Then, etching is made, layers 47, 46, and 45 are remained only on the gate region, and an n-type source and drain region 43 is diffused and formed in the substrate 41 on both sides of the mask which is the layers 47, 46 and 45. Thereafter, a region 53 is covered by an SiO₂ layer 54, a photoresist-pattern 58 is provided, P impurities are diffused, an Si₃N₄ film 66 is completely made to be PSG, planson washing is performed, the film 66 is removed and only a gate electrode 57 is remained.

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