SEMICONDUCTOR DEVICE AND MANUFACTURE THEREOF

PURPOSE:To prevent contamination on ion implantation and deterioration caused by a knock-on effect by implanting ions, penetrating an insulating film consisting of an AlN film, laminating a protective film composed of SiN onto the AlN film and thermally treating the whole. CONSTITUTION:An AlN film 14 is applied onto a GaAs substrate 1. Ions are implanted in order to form a source region 3 and a drain region 4, using a photo-resist 8 as a mask. A photo-resist mask 8' is removed completely, and an SiN film 14' is laminated. The whole is thermally treated in hydrogen. The SiN film 14' is etched through dry etching employing a fluorine group gas, using a photo-resist 8'' as a mask, and the AlN film 14 is etched in a wet type by H3PO4. Source-drain electrode materials 15, 15', 15'' are evaporated, and the SiN film 14' is etched through a dry etching method and the AlN film 14 through wet type etching respectively, employing the photo-resist 8'' as the mask. Accordingly, contamination on ion implantation and deterioration caused by a knock-on effect are prevented.