Influence of carbon sources on thermal stability of C- doped base InP/InGaAs heterojunction bipolar transistors

摘要

We report effects of annealing on InP/InGaAs heterojunction bipolar transistors (HBTs) having an InGaAs base layer C-doped using CBr_4 or CBrCI_3 as the C source. It was found that ramp thermal annealing (RTA) after growth removes H atoms, which are located in C-dopedd InGaAs base layer and deactivate C acceptors, resulting in a decrease of base sheet resistance. An RTA simultaneously can deteriorate the C-doped base layer. An evaluation of base sheet resistance and dc current gain indicates that InP/InGaAs HBTs with C-doped InGaAs grown using CBrCl_3 are more stable in terms of thermal stress than those grown using CBr_4.