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-degrees-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-degrees-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.