We demonstrate that GaAs-based HBTs with very low base currents at both low and high injection levels can be achieved using either Al0.35Ga0.65As or InGaP in the emitter with the proper optimization of structure and growth. We observe an order of magnitude reduction in space charge recombination current as the Al composition, and hence the energy-gap, of the emitter increases from 25% (1.77 eV)...

The interaction between transferred-electron effect and base widening under transient conditions in III-V heterojunction bipolar transistors is considered. Modification of the collector field profile with an n+ doping spike is shown to cause a time delay for the onset of Kirk effect creating conditions for the inception of charge instabilities. Numerical simulations suggest the possibility of s...

ABSTRACT Space and other DoD systems require high reliability components, which will survive a long mission life. Heterojunction Bipolar Transistors (HBT’s) are key components in these systems. NGST has developed a robust system for long term testing of HBT’s at very high current densities (200-300 kA/cm). This test measures current enhanced degradation that may not appear with standard high te...

Modern communications require high linearity for power amplifiers. GaAs heterojunction bipolar transistor (HBT) based amplifiers are proven to have high efficiency, good linearity, ruggedness, and low cost. In this paper we report on an improved linearity GaAs HBT device achieved through a novel engineered Ft curve. The novelty of the solution relies on the flatness of the Ft curve with device ...

The Georgia Tech team developed state-of-the-art GaN heterojunction bipolar transistor (HBT) technology in this NSF program. Throughout the project period, baseline device fabrication and material growth techniques were actively studied and significant technological advancement was achieved in III-Nitride (III-N) HBT research. We successfully demonstrated high-current gain (> 100) InGaN HBT on ...

The effects of Shockley–Read–Hall, Auger, radiative, and intrinsic surface base recombination processes in the emitter-base space-charge region on the current gain of Pnp AlGaAs/GaAs heterojunction bipolar transistors are analyzed. At low forward emitter-base bias, the current gain of a typical Pnp AlGaAs/GaAs heterojunction bipolar transistor is shown to be reduced substantially below its valu...