METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To suppress the variations of the recessing amount caused by etched back polysilicon filling the trench and to accordingly reduce the variations of the threshold voltages in a trenched semiconductor device. SOLUTION: A substrate 1 where the trench 3 is formed is put in the reaction chamber of a low pressure CVD device. The trench is filled with polysilicon 6 by a low pressure CVD method. Thermal treatment is performed at 550°C to 600°C while the reaction chamber is continuously purged with nitrogen gas. The trench is filled with polysilicon 6 whose crystal grain size is small. Then, dispersion of the subsiding amount of polysilicon in the trench by etching back of polysilicon 6 is made small. COPYRIGHT: (C)2004,JPO&NCIPI