in a method of manufacturing a semiconductor device having a capacitor constituted by a lower electrode , an upper electrode , and a dielectric film arranged between the lower and upper electrodes , a polysilicon film containing a group v element as an impurity is formed . the first etching step of forming an uneven portion on a surface of the polysilicon film is performed . the second etching step of forming an uneven portion on the surface of the polysilicon film is performed . the second etching step has an etch rate whose impurity concentration dependency is different from an impurity concentration dependency of an etch rate of the first etching step , thereby forming the uneven portion on the surface of the polysilicon film .