Properties of highly resistive and nonstoichiometric GaAs film grown by low-temperature metalorganic chemical vapor deposition using tertiarybutylarsine

The properties of highly resistive and nonstoichiometric GaAs films grown by metalorganic chemical vapor deposition (MOCVD) at low temperature (LT) are studied by transmission electron microscopy (TEM), photo-luminescence (PL), deep level transient spectroscopy, and double crystal X-ray and X-ray photoelectron spectroscopy. GaAs films are grown with source precursors of triethylgallium (TEGa) and tertiarybutylarsine (TBAs) at substrate temperatures of 425-550°C. The microstructure observed in the MOCVD GaAs film shows better film quality as the input V/III molar flow ratios increase. Furthermore, the growth rate and the shift of binding energy for the As 3d core level of the film are slightly increased with increasing V/III ratio, but the intensity of V_As-related emission in PL is decreased. We suggest that the high resistivity of the LT-MOCVD film is due to structural defects caused by the nonstoichiometry of excess As atoms in the film.