Method of manufacturing semiconductor device

In which a semiconductor chip (6) through the plasma plasma is divided into separate sections in the process, covering the formation of active layer (41) SiO2 layer (42) and cover (43) is used as a etching stop layer used to buffer the etched and cut the chip of the primary (40) first slice of plasma etching rate fluctuation in the steps. Then, with the second slice of plasma procedure, which used to be high etch rate the second plasma etching etching slices of gas cut off by the first step of etch stop layer exposed by, and prevent the protection plate (30), causing thermal damage when exposed to a plasma for a long time.