Compound formation and large microstrains at the interface of II-VI/III-V semiconductors detected by Raman spectroscopy

摘要: ZnSe epitaxial layers grown by different methods on GaAs (100) substrates were studied micro-Raman spectroscopy. At the interface formation of a Ga-Se compound, very probably zincblende defect structure Ga2Se3, is observed. This situations similar to that found in II-VI/III-V heterosystems CdTe/InSb and CdS/InP. There thermodynamically favoured III-VI compounds (In-Te In-S respectively) also detected at interface. As consequence analysis strains II-VI overlayers has take into account these interfacial reacted regions Micro-Raman spectra taken (110) cleavage plane close (200 nm) ZnSe/GaAs show large frequency shifts 2TA/TO-TA 2LO features second-order Raman but only marginal ones first-order TO scattering. The amount splitting corresponds pressures up 40 kbar (second-order scattering) few (first-order scattering). behaviour can be explained assuming Ga2Se3 forms clusters Their size should intermediate between wavelengths near-zone-centre phonons (100 scattering process those zone boundary (1 responsible for spectra.