Competitive evolution of the fine contrast modulation and CuPt ordering in InGaP/GaAs layers
نویسندگان
چکیده
We use transmission electron microscopy to characterize the morphology of InGaP epitaxial layers grown by metal-organic vapor-phase epitaxy over misoriented GaAs ~001! substrates, with a cutoff angle in a range from 0° to 25°. The occurrence of phase separation and CuPt-type ordered superstructures has been observed. The most ordered configuration has been found to appear in layers grown on 2° off substrates, and the strength of order decreases with increasing the misorientation angle beyond a52°. Conversely, whereas the phase separation is less evident in the layer grown at 2°, the sample grown with a misorientation of 25° exhibits the most phase separated configuration. The completion between these two phenomena is discussed depending on the misorientation angle. © 1996 American Institute of Physics. @S0021-8979~96!08218-7#
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