1.3-μm laser diode with a high-quality C-doped InAlAs

Carbon doping is a promising technique for making p-type layers of InAlGaAs material systems, because of its low diffusion characteristics. We have already achieved the carbon doping with low oxygen contamination. However, in the growth procedure, we used preferably low growth temperature. In this paper, we have investigated phase separation in InAlAs and growth conditions for carbon doping at higher temperatures. Through measurements of the laser characteristics, we confirmed that a carbon-doped InAlAs layer, which does not show phase separation, has superior quality to a zinc-doped layer.