Method of manufacturing semiconductor capacitor electrode

摘要

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, it preferably etching the more highly doped crystal grain borders. 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, preferably lower, and increases the width of recessed portions produced by the first etching step. It also removes porous silicon left by the first etching step.