JPS56161657A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To form an electrode window with alleviated step by forming a low melting point fiom on a substrate on which an insulating film and a surface stabilized film are formed, smoothing the end face of the window and then etching the overall surface, thereby maintaining high accuracy of a diffused layer. CONSTITUTION:In steps of manufacturing an MOSFET, an ion injection layer 5 is formed, a PSG film 9 is accumulated, a PSG film 10 in which Ge having a melting point lower than the film 9 is doped is coated on the overall surface, and a window 8 is formed at the film 10. Subsequently, it is heat treated at low temperature (-1,000 deg.C), the end face 7 of the window of the film 10 is formed in a smooth shape 7', and source and drain diffused layers 6 are simultaneously formed. Thereafter, the film 10 is all removed, for example, by a dry etching to form a window at the film 9 and the oxidized film 2 of the surface of the substrate, and an electrode window 8' having smooth end face is thus formed. Thus, it can alleviate the step of the window, and since it is not treated at high temperature, its diffusing accuracy can be highly maintained.