METHOD OF FORMING DEVICE ISOLATION REGION

摘要

PURPOSE: A method of forming a device isolation region is provided to improve an integration degree of a semiconductor device, and to be easy for a process. CONSTITUTION: In a method of forming a device isolation region, a pad oxide film(11) and a pad nitride film(12) are formed on a semiconductor substrate(10). A first device isolation formation region of the semiconductor substrate(10) is exposed by etching the pad oxide film(11) and the pad nitride film(12). The exposed semiconductor substrate(10) is etched to form a trench(12). An insulation film is deposited on an entire surface of a resultant structure so as to fill the trench sufficiently, and is etched back until a surface of the nitride film(12) is exposed. Thus, a first device isolation film(14) is formed in the trench(13). The pad nitride film(12) is etched, and then a second device isolation film(15) is formed by oxidizing an exposed pad oxide film(11).