| 摘要 |
PROBLEM TO BE SOLVED: To prevent dimples from being left on the surface of an isolation oxide film formed in a trench. SOLUTION: A layer 14 of softening material such as boron which decreases the glass softening point is formed as buried in a CVD oxide film 6 as deep as prescribed by implantation of ions or thermal oxidation carried out in vapor phase, liquid phase or solid phase. Thereafter, the CVD oxide film 6 is thermally treated so as to melt its part adjacent to a non-close contact surface 5, whereby a dimple 12 is filled up. By this setup, the surface of the CVD oxide film 6 is turned smooth, and an isolation oxide film free from dimples 12 is formed.
|
