| 摘要 |
PURPOSE: To improve emitter injection efficiency in spite of low base resistance, and reduce crystal defect, by making a base layer contain first impurities for determining a first conductivity type whose addition concentration is lower than that of the second impurities, in addition to the second impurities for determining a second conductivity type. CONSTITUTION: The part constituted of an N<+> type buried diffusion layer 13, an N<-> type epitaxial silicon layer 15, and an element isolation region 19 corresponds to a first conductivity type silicon base 21, a part of which is made a collector layer. On the silicon base 21, a second conductivity type silicon layer 23 is formed which contains, in addition to boron (B) as second impurities for determining a second conductivity type, arsenic (As) as impurities for determining a first conductivity type whose addition concentration is lower than that of the second impurities and higher than or equal to 1×10<18> cm<-3> . The silicon layer 23 is made a base layer.
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