組成傾斜InGaAsSbベースを有するDHBTにおけるアンチモンの拡散について

抄録

The impact of the growth order on the Sb diffusion from compositionally-graded-InGaAsSb/highly-doled-GaAsSb base of double heterojunction bipolar transistors (DHBTs) is discussed in this paper. For the conventional emitter-up DHBT wafer, the shift of x-ray diffraction peak of InGaP emitter due to the incorporation of a few percent of Sb is found. On the other hand, there are no pronounced peak shift when the growth order is inverted for the transfer-substrate (TS) DHBTs. Transmission electron microscopy reveals that the abruptness of the emitter-base interface of conventional wafer and base-collector interface of the wafer for the TS-DHBT are degraded. This interface degradation is due to the Sb diffusion into the upper layer of GaAsSb/InGaAsSb base.