SELECTIVE OXIDIZING METHOD AND MANUFACTURE OF SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To suppress occurrence of a bird's beak in a selective oxidizing method. SOLUTION: A silicon nitride film 16 is formed on the surface of an amorphous silicon layer 14 using a vertical low pressure thermal CVD system. An insert speed is raised to 300-600 [mm/min] or the heating temperature at inserting is lowered to 400-600 [ deg.C] so that no poor thermally oxidized film is grown on the surface of the amorphous silicon layer 14 when a semiconductor substrate 10 is inserted into a reactive chamber of the thermal CVD system. After a hole corresponding to a gate electrode pattern is formed at the silicon nitride film 16, the surface of amorphous silicon layer is selectively oxidized with the silicon nitride film 16 as a mask. As a result, such silicon oxide films 18A and 18B as have little bird's beak are provided. The material for elective oxidizing may be a single crystal silicon or polysilicon.