METHOD FOR FORMING TRENCH ISOLATION FILM OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming a trench isolation film of a semiconductor device is provided to prevent a void forming within the trench isolation film and to prevent the semiconductor device from being deteriorated by the stress due to the volume expansion of the trench thermal oxide film. CONSTITUTION: A pad oxide film(102) and a hard mask layer(104) are successively formed on the semiconductor substrate(100). A pad oxide pattern and a hard mask pattern(104) exposing a device isolation area of the semiconductor substrate are formed by a photolithography process and an etching process. A trench(106) is formed by dry-etching. A thin thermal oxide film is formed at the inner wall of the trench and the oxide film is removed by the wet etching. An oxide film is formed on the results by following to the step. A silicon nitride liner(112) is formed on the oxide film by following to the step. The trench is filled by filling the trench filling insulation film(114) having an excellent gap-fill characteristic on the results having the silicon nitride liner. The result is annealed at a fixed temperature in order to prevent the recess of the trench filling insulation film. The trench filling insulation film is flattened by the CMP process.