A dependence of the interdiffusion in InGaAs/InGaAsP multiple quantum well structures upon the stoichiometry of SiOx and SiNx capping layers, which were deposited with different SiH4 flow rates by plasma-enhanced chemical vapor deposition, was studied. Decreasing the SiH4 flow rate during plasma-enhanced chemical vapor deposition produced relatively more voids inside SiOx or SiNx film. For both SiOx and SiNx capping layers, the blue shift of intermixed samples after rapid thermal annealing becomes larger due to the enhancement of the interdiffusion of well/barrier caused by the increased porosity of dielectric capping layers as SiH4 flow rate decreased from 300 to 20sccm. Using SiOx (SiNx) deposited with different SiH4 flow rates, the magnitude of blue shift was varied by about 98nm (75nm) for the samples annealed at 850C for 30s. The blue shifts of 138 and 98nm of photoluminescence peak wavelength for the SiOx (deposited with 20sccm SiH4) capped multiple quantum wells without and with an InGaAs cap layer, respectively, were observed after rapid thermal annealing (850C, 30s).

Effect of the Property of Dielectric Capping Layers on Impurity-Free Vacancy Diffusion in InGaAs/InGaAsP MQW Structures. J.S.Yu, K.S.Chung: Semiconductor Science and Technology, 2007, 22[8], 919-24