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△ [21p-H112-12] High-quality InSb growth by metalorganic chemical vapor deposition
Keywords:InSb,MOCVD
We have investigated the electron transport properties and crystallinity of InSb films deposited on GaAs substrates. The films were grown by metalorganic vapor phase epitaxy with trimethylindium and trisdimethylaminoantimony as In and Sb sources. Using a two-step growth method and investigating growth conditions extensively, we found that the electron mobility of films either 1.0 or 1.5 mm thick strongly depended on the temperature at which the first layer (25 nm thick) was grown. The highest mobility, 61,200 cm2V−1s−1, was obtained at growth temperature of 260ºC and the smallest full-width at half maximum (FWHM) of the X-ray deflection rocking curve, 205 arcsec, was obtained at 320 °C. These mobility and FWHM values, both of which are for a total InSb thickness of 1.5 mm, are superior to those of InSb films grown by molecular beam epitaxy. Secondary ion mass spectrometry measurements showed that below 340 °C the carbon impurity concentration increased drastically with decreasing growth temperature. This carbon incorporated InSb indicated p-type behavior at low temperature by Hall measurement. These results suggest that high concentrations of carbon impurities compensated the extrinsic electrons generated from InSb/GaAs interfacial dislocations.