| 摘要 |
PURPOSE:To realize a resistance element simultaneously having a high resistance region and a low resistance region by making the film thickness of a polycrystalline layer in the low resistance region thicker than that of the polycrystalline silicon layer in the high resistance region and forming an insulating film onto at least the high resistance region. CONSTITUTION:An insulating film 302 is shaped onto a semiconductor substrate 301, and a polycrystalline silicon film 303 is formed onto the insulating film 302. The film thickness of the polycrystalline silicon layer 303 is made the same as that of a low-resistance region wiring region 304. A first silicon oxide film 305 is shaped through thermal oxidation, a nitride film 306 is formed onto the film 305, and a resist is formed to sections except a high resistance region and the nitride film 306 is removed by hot phosphoric acid. The polycrystalline silicon layer 303 is thermally oxidized to shape a second silicon oxide film 307. The whole is thermally oxidized so as to leave the polycrystalline silicon layer 303 as a high resistance region 309 at that time. The nitride film 306 is gotten rid of by hot phosphoric acid, and the wiring region 304 is formed. |
