| 摘要 |
PROBLEM TO BE SOLVED: To form trench isolation having a flat surface by embedding an insulating film for isolation by using an HDP-CVD method without being affected by the area and the degree of crowding of an active region. SOLUTION: After an element isolation trench 104 is formed in a semiconductor substrate 101, an HDP oxide film 108 is formed by using the HDP-CVD method. The HDP oxide film 108 on a large area active region 106 is etched by using a resist film 109 as a mask, and a first etching trench 110 is formed. The HDP oxide film 108 on a small area crowding active region 107 is etched by using a resist film 111 as a mask, and a second etching trench 112 is formed. The HDP oxide film 108 which is formed on a small area isolating active region 105, the large area active region 106 and the small area crowding active region 107 is polished and eliminated, and an insulating film 108a for isolation whose surface is flattened is formed only in the element isolation trench 104.
|
