| 摘要 |
PROBLEM TO BE SOLVED: To provide an SiGeC heterojunction bipolar transistor in which high speed operation can be sustained at the time of high collector current, and its manufacturing method. SOLUTION: An exemplary SiGeC heterojunction bipolar transistor has a collector comprising an n-type single crystal Si layer and an n-type single crystal SiGe layer. The base of the transistor comprises a heavily doped p-type single crystal SiGeC layer, and its emitter comprises an n-type single crystal Si layer. At the heterointerface of the n-type single crystal SiGe layer and the p-type single crystal SiGeC layer, a band gap of the p-type single crystal SiGeC layer is not smaller than the n-type single crystal SiGe layer. Even when the effective neutral base is enlarged by the increase of collector current, no energy barrier is formed in a conduction band at the heterointerface of the n-type single crystal SiGe layer and the p-type single crystal SiGeC layer. Since diffusion of electrons is not impeded, the heterojunction bipolar transistor capable of sustaining high speed operation even under a heavily doped state can be obtained and the performance of a circuit employing the transistor can be enhanced. COPYRIGHT: (C)2003,JPO
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