MANUFACTURE OF SEMICONDUCTOR DEVICE

PURPOSE: To resolve a problem, such as a wiring short circuit by thermally treating and removing a by-product generated at a dry type etching stage at a temperature higher than the boiling point of the by-product. CONSTITUTION: A gate oxide film 31, a polysilicon layer 32, a WSi2 layer 33, a first HTO layer 34 and a photoresist film (not shown) are laminated successively on a semiconductor substrate 30, and patterned, the first HTO layer is etched by a dry type, while using the resist film as an etching mask and a resist pattern is removed. The WSi2 layer 33 and the polysilicon layer 32 are successively etched by the dry type while using a first HTO pattern 34a as the etching mask, and a gate having a polycide structure consisting of a polysilicon layer pattern 32a and a WSi2 layer pattern 33a is formed as shown in Fig. D. When heat treatment is conducted at a temperature higher than the boiling point of a by-product formed at the time of etching in a non-oxidizing atmosphere, a leakage current between the gate and pad polysilicon formed in a succeeding process can be minimized.