Heterojunction bipolar transistor and integrated circuit device using the same

Claim 1

A semiconductor integrated circuit device comprising: a photoreceiver opto-electro integrated circuit obtained by forming a heterojunction bipolar transistor on a first portion of a semiconductor substrate; and a pin photodiode formed on a second portion of the semiconductor substrate, said heterojunction bipolar transistor comprising: a collector contact having a first semiconductor layer of a first conductivity type and formed on said first portion of the semiconductor substrate; a collector region stacked on said collector contact, a base having a second semiconductor layer of a second conductivity type formed on said collector region, and an emitter having a semiconductor layer of the first conductivity type formed on said base layer, said collector region including: a third semiconductor layer, a fourth semiconductor layer of the second conductivity type having an impurity concentration higher than that of said third semiconductor layer, and a fifth semiconductor layer of the first conductivity type having a band gap energy higher than that of each of said first and third semiconductor layers and an impurity concentration larger than that of said third semiconductor layer, and lower than that of said first semiconductor layer, wherein said fifth semiconductor layer, said fourth semiconductor layer, and said third semiconductor layer are sequentially formed on said collector contact, said pin photodiode comprising: said first semiconductor layer of the first conductivity type formed on said second portion of the semiconductor substrate, an intermediate layer obtained by sequentially stacking said fifth semiconductor layer, said fourth semiconductor layer, and said third semiconductor layer on said first semiconductor layer, and said second semiconductor layer of the second conductivity type formed on said intermediate layer.