COMPARATIVE-STUDY ON THE LOW-PRESSURE METALORGANIC VAPOR-PHASE EPITAXIAL-GROWTH OF INSB ON GAAS WITH TRIMETHYLANTIMONY AND TRIETHYLANTIMONY AS SB PRECURSORS

The aim of our investigations was to deposit high quality InSb epitaxial layers on GaAs substrates by low pressure MOVPE (metalorganic vapor phase epitaxy). The growth of InSb was studied at total pressures of 20, 100 and 200 hPa. Trimethylindium (TMIn) and trimethyl- or triethylantimony (TMSb, TESb) were used for the growth of InSb. Because of the relatively high thermal stability of these standard Sb precursors, only growth conditions implying a high cracking efficiency (low carrier gas velocity, high total pressure (greater-than-or-equal-to 100 hPa)) could be used to deposit high quality InSb material. Generally, the quality of the layers improved with increasing thickness, as indicated by X-ray diffraction curve widths and electron mobilities. We achieved maximum electron mobilities of 58,000 cm2/V.s and an intrinsic carrier concentration of 2 x 10(16) cm-3 at 300 K by the use of both TMSb and TESb (layer thickness almost-equal-to 2.5 mum) at a total pressure of 200 hPa. However, due to the lower thermal stability of TESb compared to TMSb, the lower consumption of the Sb precursor material (lower V/III ratios) makes TESb preferable to TMSb for the growth of high quality InSb material by LP-MOVPE.