GROWTH OF GASB AND INSB BY LOW-PRESSURE PLASMA MOVPE

High-quality InSb and GaSb epitaxial layers were grown by low-pressure plasma metalorganic vapor deposition (p(tot) = 20 hPa). Studies were made on the effect of growth temperature, V/111 ratio and precracking the Sb-precursor TESb in a DC hydrogen plasma on the growth kinetics and material quality. For GaSb growth, a comparative study with TMGa and TEGa as Ga precursors revealed the combination of TEGa and TESb to be more convenient with respect to growth efficiency and suitable V/III ratios. An additional TESb precracking did not exhibit any further improvement of the layer quality (on GaAs substrates: mu300K = 600 cm2/V.s, P300K = 5 X 10(16) cm-3, mu77K = 2700 cm2/V.s, p77K = 9 X 10(15) cm-3 ). For the temperature dependence of the growth rate of InSb (TMIn, TESb) on GaAs we observed a shift of the kinetic branch towards lower temperatures with TESb precracking. Additionally, the strong enhancement of the growth efficiency points to the reduction in the kinetic barrier due to plasma precracking of TESb. At 750 K, the best electrical material quality was achieved with TESb precracking (mu300K = 35,000 cm2/V.s, n300K = 2 x 10(16) cm-3; without TESb plasma: mu300K = 2000 cm2/V.s, n300K = 7 X 10(17) cm-3).