MANUFACTURE OF SEMICONDUCTOR DEVICE

PURPOSE:To reduce the crystal grain diameter of a polycrystalline silicon film and almost eliminate the variation in resistance values of resistors with fine structures by a method wherein an insulating film having a rough surface is formed and the polycrystalline silicon film doped with impurities is formed on the insulating film. CONSTITUTION:A thermal oxide film 12 is formed on a P-type silicon substrate 11. An Ar plasma is applied to the surface of the thermal oxide film 12 to increase dangling bonds in the surface. An oxide film which is formed by a CVD method instead of the above mentioned method may be used. After that, a phosphorus-doped polycrystalline silicon film is formed by an LPCVD method and subjected to a thermal treatment in a nitrogen atmosphere. With this constitution, the crystal grain diameter of the polycrystalline silicon film can be reduced. Further, the variation in resistance values of resistors with fine structures can be almost eliminated.