| 摘要 |
PURPOSE:To readily flatten the surface of a PSG film without producing pinholes or a finely irregular surface in a short time by employing the step of etching the film for flattening with aqueous fluoric acid solution of fast etching speed of the PSG with a photoresist as a mask. CONSTITUTION:After an LOCOS oxidized film, a gate oxidized film, a polysilicon gate, and source and drain diffused layer are formed and processed on a silicon substrate 1 and a PSG film 2 of an interlayer insulating film to cover them is formed, wirings 3 of lower layer aluminum is formed. Then, a PSG film 4 is covered, and a positive type photoresist 5 is covered thereon. Then, the photoresist of the raised portion of the surface of the film 4 is completely exposed, the photoresist 5 is exposed to the degree that the photoresist disposed in the recess of the surface of the PSG film becomes insufficient in the exposure to develop it. Then, the raised portion of the surface of the film 4 is exposed, and the photoresist 5' remains on the recess. Thereafter, with the photoresist 5' as a mask the surface of the film 4 is etched until the surface substantially becomes substantially flat at the position that the surface is matched to the recess surface, and the photoresist 5' is then removed by etching. |
