| 摘要 |
PURPOSE:To enable to form a thick field insulation film on a p type semiconductor region by selective oxidation by a method wherein the p type semiconductor region is formed in an n type semiconductor substrate, and an n type resistance element is formed in the region. CONSTITUTION:An oxide film 22 of a fixed thickness is formed over the entire surface of the n type semiconductor substrate 21. Next, the p type region 23 is provided at the fixed region of the substrate 21 by means of p type impurity. Further n type impurity is implanted into the p type region 23, resulting the resistance element 24 composed of an n type semiconductor. On the other hand, an oxidation resistant protection film composed of an Si nitride film is formed on the oxide film at the desired region of the substrate 21, and, with the film as the mask, thick oxide films acting as the field insulation films 28 are selectively formed. Thereafter, th base 25, and the emitter 26, and Al wirings 27 are formed at the desired region. As the result, a semiconductor device having no restrictions in wiring and characteristic variation and with less stepwise difference can be obtained. |
