Characteristics of InGaP/GaAs heterojunction bipolar transistors (HBTs) with sulfur treatments

The characteristics of the InGaP/GaAs heterojunction bipolar transistors (HBTs) with sulfur treatment are studied and demonstrated. Based on the use of sulfur passivation, the series resistance of a base-emitter B-E junction can be effectively reduced and the series resistance dominant regimes (decrease of current gain) are presented at a higher collector current regime. The device with sulfur treatment can be operated under extremely low collector current (IC≅10−11A) region, which offers the promise for low-power electronics applications. It is known that, from experimental results, the too long time for sulfur treatment is not necessary. Furthermore, the studied devices with sulfur treatment can remarkably reduce the collector-emitter offset voltage ΔVCE and emitter size effect, and improve the high-frequency performance.