Extrinsic base surface recombination current in GaInP/GaAs heterojunction bipolar transistors with near-unity ideality factor

Devices demonstrating near-ideal I-V characteristics are fabricated to examine the ideality factor for extrinsic base surface recombination in GaInP/GaAs HBTs. These HBTs with various emitter areas have either passivated or exposed extrinsic base surfaces. Comparison of the passivated and unpassivated devices' characteristics indicate that the ideality factor value of the surface recombination is as close to unity as 1.05. The ideality factor value is bias dependent, decreasing to values of 1.6 at lower base-emitter biases.