Oxygen plasma induced degradation in InGaAs/InP heterostructures

The effects of oxygen plasma conditions on the performance of InGaAs/InP he terostructure bipolar transistors (HBTs) have been studied by comparing the HBT's characteristics, such as current gain and breakdown voltage, before and after treatment. The base-emitter junction characteristics of InGaAs/In P HBTs were unaffected by oxygen plasma treatments, for exposure periods of up to 10 min and rf powers <200 W. Higher rf powers degrade the current ga in. In contrast, the base-collector junction was degraded even for short pe riods and low rf powers; the base-collector leakage current increased and t he breakdown voltage decreased. Further reduction of the current gain was o bserved when dielectric films were deposited by plasma-enhanced chemical va por deposition on oxygen treated devices. The dielectric film does not redu ce the gain of devices that were not treated by oxygen plasma. (C) 2000 Ame rican Vacuum Society. [S0734-211X(00)09906-6].