Early variations of the base current in In/C-doped GaInP-GaAs HBTs

This paper reports on the early variations of the base current (burn-in effect) in SiN passivated, double-mesa processed, In/C-doped GaInP-GaAs HBTs induced by stressing the devices at room temperature and under different bias conditions. The investigation was carried out by means of DC measurements and low frequency noise analysis, in the 250 Hz-100 kHz frequency range. The results demonstrated that the burn-in effect is due to a reduction of surface recombination currents in the extrinsic base region around the emitter perimeter. This reduction in surface recombination current is attributed to the passivation of defects at the passivation/semiconductor interface by hydrogen atoms debonded from C-H complexes in the base layer during the stress.