| 摘要 |
<p>A semiconductor device includes a first semiconductor region (11), a second semiconductor region (12), a third semiconductor region (13), and a fourth semiconductor region (14). The first semiconductor region (11) is a collector region of a first conductivity type. The second semiconductor region (12) is provided on the first semiconductor region (11) and serves as a collector region whose impurity concentration is lower than that of the first semiconductor region (11). The third semiconductor region (13) is provided in the second semiconductor region (12) and serves as a base region of a second conductivity type. The fourth semiconductor region (14) is provided in the third semiconductor region (13) and serves as an emitter region of the first conductivity type. The second semiconductor region (12) is thinner than a depletion layer formed in the collector region when a potential difference between the base region and the emitter region is substantially equal to a potential difference between the collector region and the emitter region. <IMAGE></p> |
