REAL-TIME OBSERVATIONS OF APPEARANCE OF CROSSHATCHED PATTERN DURING MOLECULAR-BEAM EPITAXY OF COMPRESSIVE INGAAS ON INP

The microscopic surface features were observed during molecular beam epitaxy of In0.65Ga0.35As on InP (100) substrates by scanning microprobe reflection high-energy electron diffraction in real time. During growth, a narrow line with low contrast appeared along the [011BAR] direction after about 750 angstrom of growth; the line increased in contrast, density and width as the growth proceeded, and finally formed a clear crosshatched pattern. A cross-sectional transmission electron microscope observation showed that the presence of a surface crosshatched pattern is directly correlated with the presence of interfacial misfit dislocations. The results indicate that the thickness at which the crosshatched line appears represents the critical layer thickness corresponding to misfit dislocation generation.