METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

摘要

A method for manufacturing a semiconductor device is provided to lower a poly-resistance and to an electron speed by removing a seam from an amorphous silicon gate. A trench is formed on a substrate. A chemical dry-etch process is performed to round an edge part of the trench and to improve surface roughness of a sidewall of the trench. A gate insulating layer is formed on the chemically dry-etched sidewall of the trench. The trench including the gate insulating layer is filled with amorphous silicon. A polysilicon gate(135) is formed by performing a thermal process for the substrate including the amorphous silicon. A semiconductor device is formed with a power MOSFET. The thermal process is performed at the temperature of 620 to 650 degrees centigrade.