| 摘要 |
PURPOSE:To realize a minute emitter region by a method wherein the emitter region and a collector region are formed with an annular pattern as a mask and, while the annular pattern is remaining, a layer insulating film is deposited and removed by selective etching to form contact holes. CONSTITUTION:After an N-type silicon layer 22, an N<+> type buried layer 23 and a P<+> type element isolation region 24 are formed on a substrate 21, a field oxide film 26 is formed. Then an oxide film 27 is made to grow on the surface of a base region 25 and a polycrystalline silicon film is deposited over the whole surface and patterned to form an annular polycrystalline silicon pattern 28. After P-type impurity ions are implanted with the silicon pattern 28 as a mask, a P-type emitter region 29 and an annular P-type collector region 30 are formed. Successively, an oxide film 31 is formed on the surface around the pattern 28 and the exposed surface of the base region 25 and, after a CVD- SiO2 film 32 and a silicon nitride film 33 are deposited, contact holes 35 are formed by selective etching and then Al electrodes 36-38 are formed.
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