| 摘要 |
<p>PURPOSE:To prevent the deterioration of transistor characteristics due to the residual resistance effect and current concentration effect and lessen the chip size by providing a light entrance window or the electrodes in emitter area section of bipolar transistor-type optical semiconductor device. CONSTITUTION:A P-type semiconductor layer 12 is formed to comprise a base area on an N-type semiconductor layer 11 forming a collector area, and further an N-type semiconductor 13 is formed to comprise an emitter area on the layer 12. Then, electrodes 14 are provided on the layer 13 and simultaneously the area on the emitter area excluding the electrodes 14 is used as a light entrance window 15. Thanks to such construction, the enlarged emitter area can be utilized as it is as a light absorbing area, resulting in reduction of chip area. On the other hand, when a light 18 enters uniformly, collector current will flow evenly in a whole emitter area and there occurs no lowering of transistor efficiency resulting from the concentration of collector current to the periphery of emitter.</p> |
