METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for manufacturing a semiconductor device is provided to prevent a damage on a substrate by controlling a thickness range of a gate oxide layer. CONSTITUTION: A gate insulating layer(22) and the first polysilicon layer(23) are formed on the first conductive type semiconductor substrate(21). The second conductive type dopant of the first density is implanted on one region of the first polysilicon layer(23). The second conductive type dopant of the second density is implanted on the other region of the first polysilicon layer(23). A diffusion barrier(25) is formed on the first polysilicon layer(23). The second polysilicon layer is formed on the diffusion barrier(25). A gate electrode(26) is formed by removing selectively the second polysilicon layer, the diffusion barrier(25), the first polysilicon layer(23), and the gate insulating layer(22).