THERMAL-STABILITY OF NEARLY LATTICE-MATCHED ZNSSE/GAAS INTERFACE GROWN BY MOVPE

The thermal stability of ZnSxSe1-x/GaAs interfaces were investigated. Heterointerfaces for 10800 angstrom thick ZnSxSe1-x films in the nearly lattice-matched S composition range of 0.045<x<0.075 were found highly stable even after thermal annealing of 5 h at an elevated temperature of 600°C. Away from this S composition, interface diffusion increased abruptly. The change at the boundary of the two regions was extremely abrupt and the boundary was in close agreement with the calculated critical value for misfit dislocations. This indicates that the misfit dislocation originating from the heterointerfaces and the associated enhancement of the interface diffusion occur abruptly above the critical thickness. These phenomena may be more critical for nearly lattice-matched but thicker films.