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.

Abstract: A method of manufacturing a semiconductor device, includes the following steps: part of an insulation film is left on the bottom of a contact hole of the insulation film formed on a semiconductor substrate or a separate insulation film is otherwise formed, under which condition a satisfactory slope is formed on the peripheral edge and the side wall of the contact hold by providing the semiconductor substrate with a heat treatment. According to the present invention, it is possible thereafter to improve the step coverage of a metal interconnection to be formed on the surface of the insulation film and to prevent breakage of the metal interconnection, thereby substantially improving the reliability of the resulting semiconductor device.