Radical-assisted organometallic vapor-phase epitaxial growth of GaAs

For the first time, radicals have been added to assist organometallic vapor-phase epitaxial (OMVPE) growth of GaAs at low temperatures. Supplemental t-C₄H₉ radicals from the pyrolysis of azo-t-butane [(t-C₄H₉)₂N₂] were used to increase the growth rate of GaAs from trimethylgallium [TMGa, (CH₃)₃Ga] and arsine (AsH₃) at temperatures as low as 390 °C. Mass spectroscopy studies show that the added radicals enhance the decomposition rates of both TMGa and AsH₃. The GaAs growth rate was increased by a factor of 6 at 450 °C. The radical-assisted OMVPE grown samples are, indeed, GaAs based on microprobe analysis. Spectra from Raman scattering experiments further confirm that the GaAs is single crystalline.