Annealing experiments on InP/InGaAs single and double HBTs grown by molecular beam epitaxy

InP/InGaAs SHBTs (sample#1444) and DHBTs (sample#1450) have been successfully grown by solid source molecular beam epitaxy using a GaP decomposition source developed at UMIST. Thermal stability studies were performed on the heavily beryllium doped (1.5×10¹⁹ cm^-3) HBTs using post-growth annealing in an N₂ ambient. The devices were annealed between a temperature range of 350-550°C for 15 minutes prior to fabrication and their I-V characteristics compared. Excellent thermal stability was found with the major transistor parameters hardly affected up to annealing temperatures of 500°C.