METHOD FOR FABRICATING TRENCH ISOLATION IN SEMICONDUTOR DEVICE

摘要

A method for forming a trench isolation layer of a semiconductor device is provided to prevent damage of a liner nitride layer by protecting a surface of the liner nitride layer. A trench(120) is formed in a semiconductor substrate(100). A liner nitride layer(140) is formed on the semiconductor substrate including the trench. A first lower layer(151) of a first HDP(High Density Plasma) oxide layer(150) is deposited on the liner nitride layer. The first lower layer of the first HDP oxide layer is etched by using an etch source including a nitrogen fluoride gas and a methane gas. A second lower layer(153) is deposited on the first lower layer of the first HDP layer. An overhang is removed by performing a wet-etch process. A second HDP oxide layer is deposited on the first HDP oxide layer.