| 摘要 |
PURPOSE: To adaptively form a trench structure having a constant geometric figure within a substrate surface region, and the trench structure is covered to a specific depth in the top region by spacer (side face covered). CONSTITUTION: A trench mask having SiO2 is formed on a substrate 1, made of single crystal silicon. After a precipitation of a first Si3 N4 layer, a first Si3 N4 spacer 31 is formed by an anisotropic etching, and a first trenching is made to the extent within a first depth t1 . After selectively removing the passivation layer made at the first trenching and precipitating the second Si3 N4 layer, a second Si3 N4 spacer 41 is formed by an anisotropic etching, and a second trenching is made to the extent within a second depth t2 . Then, a trench structure 5 is completed. |
