The effect of rapid thermal annealing to device performance of InGaAs/AlGaAs quantum well laser diodes

Abstract

The effect of rapid thermal annealing to device performance of InGaAs/AlGaAs quantum well laser diode has been investigated using photoluminescence (PL), double-crystal X-ray diffraction (DCXRD), photo-response (PR) and lasing characteristic. X-ray measurement results show that there is an incorporation of carbon atom in lattice site of higly doped p⁺⁺ GaAs contact layer. The photocurrent spectra at room temperature reveal that the relative intensity of 1e-1hh transition of annealed samples is much higher than that of as-grown samples and the peak became narrow. Stark shifts are much higher for the samples after annealing in comparison to the as-grown samples and this has been attributed to a decrease of the confining potential due to thermal interdiffusion. Characteristic of laser diodes shows that there is no significant degradation of lasing parameters after annealing has been observed and it has been found that the threshold current of annealed laser diodes are approximately four times less than as-grown laser diodes and this has been attributed to the electrical activation of carbon.