Ordering of In and Ga in epitaxially grown In0.53Ga 0.47As films on (001) InP substrates

Abstract

Ordering of In and Ga in In0.53Ga0.47As films grown at 573 K, 673 K, and 773 K by molecular beam epitaxy was investigated by electron diffraction pattern analysis using a transmission electron microscope equipped with an Ω-filter and imaging plates. In addition, high-resolution electron microscopy on the specimens and fast Fourier transformation analyses were performed to identify the short-range ordering. In the EDPs obtained from the specimen grown at 573 K, the diffuse scattering corresponding to short-range ordering was observed only when the film was investigated at [110] beam incidence, whereas for the specimens grown at 673 and 773 K, diffuse scattering was observed only at [110] beam incidence. The ordering of 573 K specimen has a triple period and those of 673 K and 773 K have a double period. Through the processing of the HREM images and comparison of calculated and observed diffuse-scattering distribution, models of short-range ordered structures were proposed on the basis of the triple-A type ordering at the specimen grown at the 573 K and the CuPt-B type ordering at the specimen grown at 773 K. © 2006 The Japan Institute of Metals.