| 摘要 |
PROBLEM TO BE SOLVED: To provide a SiGe hetero junction bipolar transistor which has a high Early voltage and is reduced in variations of h<SB>FE</SB>. SOLUTION: A base layer formed of a SiGe mixed crystal comprises: a spacer layer 4 which comes into contact with a collector layer 3 and in which a base impurity is not diffused; and a genuine base layer 5 which comes into contact with an emitter layer 9 and in which the base impurity is diffused. The spacer layer 4 contains C at a low concentration, and the genuine base layer 5 comprises: a first region which is on the collector layer 3 side and contains C at a low concentration; and a second region which is on the emitter layer 9 side and contains C at a high concentration. COPYRIGHT: (C)2009,JPO&INPIT
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