| 摘要 |
PURPOSE:To flatten the surface of an interlayer insulating film and to eliminate the disconnection of wirings to be provided thereon by a method wherein an inorganic film is applied on an insulating film with a stepping, and when a dry etching is going to be performed on these films, the shortest distance ratio from the height of the stepping and lower end of the stepping to the surface of the inorganic film is prescribed as 1:1-3:1. CONSTITUTION:An SiO2 film 2 is coated on an Si substrate 1, Al wirings 3 and 4 of prescribed shape are formed thereon, and a PSG film 5 is coated on the substrate 1 having the stepping which is formed as above-mentioned. Then, a silica film 6 of the SiO2 concentration of 5.9wt% is coated on the film 5 whereon a stepping is generated between the top part 5a and the bottom face part 5b by the presence of the wirings 3 and 4, and the film 6 is sintered by performing a heat treatment at 90 deg.C for one minute, then at 200 deg.C for thirty minutes, and lastly, at 400 deg.C for 30min. Subsequently, the film 6 is completely removed by performing an anisotropic etching, and the film 5 having small surface stepping 5c is left. In order to have the avobe result, the height of the stepping which is generated first and the shortest distance between the lower end and the surface of the film 6 are specified in advance. |
