Growth of carbon doping Ga0.47In0.53As using CBr4 by gas source molecular beam epitaxy for InP/InGaAs heterojunction bipolar transistor applications

In this article, we present the comparison of material quality and device performance of gas-source molecular beam epitaxy (GSMBE)- and metal-organic molecular beam epitaxy (MOMBE)-grown C-doped InGaAs and npn InGaAs/InP heterojunction bipolar transistors (HBTs). The results indicate that the crystal quality of GSMBE-grown samples is comparable to that of MOMBE-grown samples. The GSMBE-grown HBTs show excellent dc and high frequency performance. The dc current gain (β) was 37 at a collector current of 21 mA and the emitter-base and base-collector junction ideality factors were 1.14 and 1.04 indicating good junction properties. For high frequency performance, the fT and fmax are around 108 and 128 GHz for a 4000 A InGaAs collector with an emitter area of 3×10 μm2. Finally, the thermal stability of C-doped InGaAs and its effects on InP/InGaAs HBT device reliability will be discussed.