| 摘要 |
PURPOSE:To facilitate stable tapered etching by applying heat treatment only on the surface layer of a photoresist before etching. CONSTITUTION:After an SiO2 film 2 is grown on an Si substratel 1, the pattern of a negative photoresist 3 is formed. Next post baking hardens the surface layer of the resist 3 to a photoresist 3'. Thereafter, when etching is done until an etching region reaches the substrate 1, the lower part of the film 2 is subjected to isotropic etching, while the upper part to tapered etching to improve the step coverage of Al 4, etc. |
