DYNAMIC-MODEL FOR PSEUDOMORPHIC STRUCTURES GROWN ON COMPLIANT SUBSTRATES - AN APPROACH TO EXTEND THE CRITICAL THICKNESS

We use a dynamic model to analyze the critical thickness for pseudomorphic structures grown on thin membranes considering the strain relaxation process. Our results show that a pseudomorphic structure of arbitrary thickness can be achieved on a semiconductor membrane which works as a compliant substrate. The analysis on GaAs/InGaAs material system shows that the membrane should be thinner than 1200 angstrom for 1% strain and 1 mum for 0.5% strain. Such thickness can be achieved by existing technology. Using the proposed method, semiconductor lasers of yellow and green colors, among many new devices, can be fabricated with strained InGaP/InAlGaP active and cladding layers on GaAs substrates.