METHOD FOR FORMING DEVICE ISOLATION FILM IN SEMICONDUCTOR DEVICES

摘要

PURPOSE: A method for forming a device isolation film is provided to minimize the loss of an active region by controlling its thickness and atmosphere when a process of forming a sacrifice oxide film and a sidewall oxide film is proceeded. CONSTITUTION: The method for forming a device isolation film deposits a pad oxide film(20) and a nitride film(30) on a semiconductor substrate(10). A portion of the substrate where a device isolation film will be formed is etched using a field mask to form a trench(50). A sacrifice oxide film is formed at the sidewall of the trench(50) by wet oxidization process of a low temperature. The sacrifice oxide film is removed using a solution containing HF. A sidewall oxide film(70) is formed at the sidewall of the substrate(10) in the trench(50) by means of wet oxidization process of a low temperature. The sidewall oxide film(70) is formed. Then, the trench(50) is filled and is then flattened to form the device isolation film.