METHOD FOR FORMING STI LAYER OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming an STI(shallow trench isolation) layer of a semiconductor device is provided to effectively prevent a dent from being formed at the interface of an active region and an isolation region by forming a liner layer composed of a polysilicon instead of a nitride layer liner. CONSTITUTION: A pad oxide layer and a mask layer are formed on a semiconductor substrate(100). The second substrate is etched to form a trench by using the mask layer. An oxide layer is formed on the inner wall of the trench. The liner layer made of polysilicon is formed on the oxide layer on the inner wall of the trench. The inside of the trench including the liner layer is filled with an isolation layer(112). The pad oxide layer and the mask layer are eliminated. The isolation layer protruding over the semiconductor substrate is planarized.