Armstrong, Westerman, Hattori, McLeland & Naughton
Heterojunction bipolar semiconductor device and its manufacturing method
 A heterojunction bipolar transistor has a support substrate, a collector layer formed on the support substrate, a base layer formed on the collector layer containing arsenic as group V element, a first emitter layer formed on the base layer, containing phosphorus as group V element, and having a band gap wider than the base layer, an emitter passivation layer formed on the first emitter layer made of semiconductor having a function of passivating the surface of the first emitter layer, and a base electrode forming an ohmic contact with the base layer. The whole upper surface of the base layer is covered with the first emitter layer and base electrode, the whole upper surface of the first emitter layer is covered with the emitter passivation layer, and the region of the first emitter layer adjacent to the edge of the base electrode is depleted throughout the full depth thereof. 
Fujitsu Limited
H H
H01L H01L
inventional inventional
Kazukiyo Tsuyoshi Shigehiko Hiroshi
Joshin Takahashi Sasa Yamada