Evaluations of strains in fused layers using patterned substrates

Strains existed in wafer fused AlGaAs/GaAs quantum wells on patterned InP substrate was systematically evaluated. The fused layers on the U-grooved substrate were characterized by scanning electron microscopy and micro-photoluminescence. Through the micro-probing technique, we observed no misfit-strain in the wafer fused interface layer but a little bit of thermal strain resulted from different thermal expansion coefficients in between GaAs and InP matrices. We successfully proved that the concept of strains existed in wafer fused layers by employing the patterned substrates.