METHOD FOR FORMING TRENCH OF SEMICONDUCTOR

A trench type gate forming method of the semiconductor device is provided to uniformly maintain the thickness of the poly stick up part of the trench by forming the etching stopping layer between the silicon substrate and the hard mask. A trench type gate forming method of the semiconductor device includes the step for forming the etching stopping layer(110) and the hard mask(120) on the silicon substrate(100); the step for forming the trench by etching the silicon substrate; the step for performing the round etching to the inside of the trench; the step for filling the trench by depositing the polysilicon layer(160); the step for the polysilicon layer and hard mask up to the etching the etching stopping layer; the step for protruding the poly stick up part from the trench by removing the etching stopping layer.