| 摘要 |
<p>Disclosed is a bipolar transistor. The bipolar transistor comprises a substrate, a collector layer, a p-type electroconductive base layer, and an n-type electroconductive emitter layer. The collector layer is provided above the substrate and comprises a first nitride semiconductor. The p-type electroconductive base layer is provided on the collector layer and comprises a second nitride semiconductor. The n-type electroconductive emitter layer is provided on the base layer and comprises a third nitride semiconductor. The collector layer, the base layer, and the emitter layer are provided in such a manner that the direction of crystal growth relative to the surface of the substrate is parallel to the [0001] direction of the substrate. The first nitride semiconductor comprises InycAlxcGa1-xc-ycN wherein 0 = xc = 1, 0 = yc = 1, and 0 < xc + yc = 1. The length of an axis a on the surface side of the first nitride semiconductor is longer than the length of an axis a on the substrate side.</p> |
