Method of forming a low resistance contact by forming a contact hole

Abstract

The invention is intended to form a recess large in the opening width at the contact hole forming position of the insulator film before opening contact holes in the insulator film, and to open contact holes smaller in opening width at the bottom of the recess. According to the manufacturing method of the invention, since the opening size of the recess in the upper portion of the contact hole may be set larger and by decreasing the shadowing effect when covering the aluminum alloy wiring layer, the degree of covering of the aluminum alloy wiring layer on the side wall of the contact hole is improved, so that reduction of contact resistance and enhancement of reliability may be achieved. Besides, since the bottom of the contact hole may be opened at high precision, mutual fine connection of wiring layers is possible, and even if the elements are integrated at high density, a proper clearance may be maintained between the contact hole and gate electrode, and thereby electrical leak between wiring layers may be effectively prevented.