Semiconductor device having a gate electrode of polycrystal layer and a

Abstract

A semiconductor device without erroneous operation and deterioration of characteristics in a transistor even when an impurity region is formed in self-alignment by ion implantation using a gate electrode as a mask, and a method of manufacturing thereof are disclosed. This semiconductor device includes a gate electrode formed of a polycrystal silicon layer 4b having the crystal orientation of the crystal grains arranged in a definite orientation. By implanting ions at a predetermined angle with respect to the crystallographic axis of the crystal grains of the polycrystal silicon layer 4b in forming a p.sup.+ impurity region 5 by ion implantation using the gate electrode as a mask, the channeling phenomenon where ions pass through the gate electrode is prevented. Therefore, generation of erroneous operation and deterioration of characteristics in a transistor are prevented in forming an impurity region in self-alignment by ion implantation using the gate electrode as a mask.