Effect of high temperature annealing on precipitate formation in carbon-doped base of InGaP/GaAs HBTs grown by LP-MOCVD

The effect of high temperature annealing on the formation of carbon precipitates in the base region of InGaP/GaAs heterojunction bipolar transistors (HBTs). This work for the first time, shows that after annealing at only 600°C, a sample doped at 5.5x10¹⁹ cm^-3 displays carbon precipitation. InGaP/GaAs HBT structures were grown for the annealing study. The annealing process not only removes hydrogen from the base but also creates carbon precipitates. DC current gain measurements imply that the carbon precipitates increase base recombination. These results are very important in the growth and post growth growth annealing of high gain HBTs.