METHOD OF FILLING A TRENCH

摘要

A method of filling a trench is provided to completely remove a remaining material from a mask pattern by filling a trench using an oxide material and removing an upper portion of the oxide material using an etching gas. A mask pattern(106) is formed on a substrate(100). A trench(108) is formed in the substrate by etching the substrate using the mask pattern. A first oxide film is formed on the mask pattern, such that the trench is buried. A CMP(Chemical Mechanical Polishing) is performed on the first oxide film, until a portion of the mask pattern is exposed. An upper portion of the first oxide film is removed by using a process gas having a predetermined etching selection ratio between a silicon nitride material and a silicon oxide material, and a recess(112) is formed to expose a portion of a side portion of the mask pattern. A second oxide film is formed on the mask pattern, such that the recess is buried.