| 摘要 |
<p>A heterojunction bipolar transistor is manufactured by using a wafer wherein a collector (12, 14), a base (16) and an emitter (18, 20) are sequentially stacked. The emitter portion (18) which contacts at least the base has a wider forbidden band gap than that of the base (14). An external base region (24) is formed to surround the emitter region. The external base region (24) extends so as to reach the base and has a recess partially exposing the base. A base electrode (30) is formed on a portion of the base exposed in the recess. A collector electrode (40) is electrically connected to the collector, and an emitter electrode (38) is electrically connected to the emitter.</p> |
