| 摘要 |
PURPOSE:To enhance controllability of the current amplification factor hFE of a bipolar transistor, and to obtain a BI-MOS semiconductor device having favorable reproducibilities of the characteristic parameters of the respective elements by a method wherein high temperature heat treatment to be performed after an emitter diffusion process is completed is omitted. CONSTITUTION:A base region 108, a source region 109 and a drain region 110 are formed, and a gate oxide film 114 is formed at an MOS transistor part. A window is opened in an oxide film 106 on the emitter forming region of a bipolar element, a silicon film 121 containing impurities in high concentration is formed to be made as a diffusion source for formation of an emitter region 112 and a collector electrode contact region 111, and moreover to be made as a gate electrode 119, and the silicon film 121 excluding the emitter region, the collector region and the gate electrode is thermally oxidized using a silicon nitride film 122 as a mask to convert into an oxide film 123 and to flatten the surface. It is unnecessary to perform high temperature heat treatment such as gate oxidation, etc. after emitter diffusion to control the hFE of the bipolar transistor is completed. |
