Feasibility of strain relaxed InAsP and InGaAs compliant substrates

With a view to investigating the feasibility of using ultrathin films as compliant substrates, we present some preliminary results concerning InAs_0.25P_0.75 (0.8% compressively-stressed on InP) film stuck onto a Si host substrate via borophosphorosilicate glass (BPSG). In an attempt to study relaxation mechanisms without any limitation on material viscosity, we also report on how a pseudomorphic In_0.65Ga_0.35As layers (0.8% compressively-stressed on InP) elastically relaxes when stuck onto a Si host substrate via a thick Apiezon wax layer. It appears that uniform and flat in-plane elastic relaxation is actually possible only for samples of small areas. For larger samples, there is a competition between undulating and sliding as stress relaxation processes. However, we think that the resulting morphology in terms of undulation periodicity and amplitude is compatible with the use of such layers as seed layers for subsequent epitaxial overgrowths.