Reduced Al-Ga interdiffusion in GaAs/AlGaAs multiple quantum well structure by introducing low hydrogen content SiNx capping layer for dielectric cap quantum well disordering

Dielectric cap quantum well disordering (DCQWD) of GaAs/AlGaAs multiple quantum well (MQW) structure was carried out by using SiNx. capping layer grown by plasma enhanced chemical vapor deposition (PECVD). By varying the NH3 flow rate with fixed SiH4 flow rate during the SiNx. growth, the characteristics of the capping film were varied. There was an increase in the energy shift of quantum well photoluminescence (PL) peak after thermal treatment of the samples with rapid thermal annealing (RTA) as the NH3 flow rate was increased, although the thickness of SiNx decreased. This is thought to be due to the increase of hydrogen content in SiNx. film grown at higher NH3 flow rate.