| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the etching rate of an insulation material for filling trenches and to avoid etching the trench filling material as the following process, by vacuum evaporation of an undoped and doped oxide films in the trenches and implanting adequate ions in the oxide films. SOLUTION: Trenches 46 are formed into inactive regions of a semiconductor substrate 40, a first undoped oxide film 48 is formed on trench resultant products, and a second doped oxide film 50 is formed on the first film 48 and reflowed. Ions are implanted in the first and the second films 48, 50 to reduce the etching rate. The films 48, 50 are etched back to remove an insulation material formed on active regions. This perfectly fills up voids 52 in the trenches and raises the etching resistivity of the oxide films filled in the trenches.</p> |
