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 VAs-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.
|Number of pages
|Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
|Published - Jun 1997
- High resistivity film
- V/III ratios