Characterization of AlInP cladding layers with Mg and Si diffusion barriers for high-power red GaInP-AlGaInP laser diodes

We investigated the doping profiles of Mg and Si dopants near the multiple quantum well (MQW) active region in 640-nm-band GaInP-AlGaInP red laser diodes (LDs). With a 200-nm-thick Mg diffusion barrier, optimal doping profiles were obtained with an Mg flow rate of 80 sccm. Without a Si diffusion barrier, significant Si diffusion into the MQW layers was observed even at the lowest Si flow rate of 25 sccm. A 100-nm-thick Si diffusion barrier effectively suppressed the Si diffusion into the MQW layers, resulting in improved laser performance. The results suggest that undoped diffusion barriers for Mg and Si dopants in AlInP cladding layers with optimal thickness will enhance the laser performance.