Semiconductor device manufacturing method

A semiconductor device manufacturing method is provided that includes etching with a plasma a multilayer film including a first film and a second film with differing dielectric constants alternately stacked on a substrate using a photoresist layer arranged on the multilayer film as a mask, and forming the multilayer film into a stepped configuration. The semiconductor device manufacturing method includes repetitively performing a first step of etching the first film using the photoresist layer as the mask; a second step of adjusting a pressure within a processing chamber to 6-30 Torr, generating the plasma by applying a first high frequency power for biasing and a second high frequency power for plasma generation to the lower electrode, and etching the photoresist layer using the generated plasma; and a third step of etching the second film using the photoresist layer and the first film as the mask.