MANUFACTURE OF SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To realize mounting of a capacitance element which relaxes the concentration of electric field, after a nitride film which is used as an insulation film of capacitor is deposited, by controlling the polysilicon surface condition to reduce the degree of projection of polysilicon. SOLUTION: When doping an impurity to a polysilicon film formed on an oxide film for element isolation, a sheet resistance value of the polysilicon film is adjusted by adjusting the doping time to control roughness of the polysilicon film surface. The surface roughness can be set to 20 nm or less, and a lower sheet resistance may be assured to manufacture a highly reliable and highly accurate capacitance element, by setting the impurity doping time to 30 minutes or less.