| 摘要 |
PURPOSE:To obtain the transistor suitable for high-speed operation as well as to form the stabilized polycrystalline Si for the titled device by a method wherein a side base is formed after an emitter region has been previded. CONSTITUTION:The part of the mark layers 82 and 83, whereon emitter and collector electrodes will be formed, are removed respectively, n type impurities of high density are introduced into the polycrystalline Si 72 and 73, and a thick Si oxide film is grown on this part by performing thermal oxidization. At this time, a part of the n type impurities of Si 72 is diffused in the main base 6, and an emitter 11 is formed. Then, the remaining masks 81 and 84 are removed, p type impurities of high density are introduced into polycrystalline Si 71 and 74, a side base 10 is formed in the base 6 by performing a thermal oxidizing process, and at the same time, the above is properly controlled by deeply diffusing the emitter 11 again so that a suitable current amplification factor hfe will be obtained. According to this constitution, as all heat treatments, starting with the formation of the main base and ending with the formation of the emitter, can be performed at a low temperature, the main base is not formed deeply. Also, a sufficient quantity of impurities can be supplied into the Si 72. |
