| 摘要 |
PROBLEM TO BE SOLVED: To provide a bipolar semiconductor device where a high current gain and a high cutoff frequency are realized in a high current region while high breakdown voltage performance is maintained and a sufficient transistor operation is possible, and to provide the manufacturing method of the device. SOLUTION: A collector is provided with a first semiconductor layer and a second semiconductor layer whose forbidden band width is narrower than the first semiconductor layer. The second collector layer has a peak inside, and impurity is doped in such a way that a peak value becomes higher than impurity concentration in any position in the first collector layer. It is desirable that concentration of doped impurity is adjusted so that a depletion layer between the collector and a base extends to the first collector. COPYRIGHT: (C)2006,JPO&NCIPI
|
