Theoretical and experimental description of the growth of GaAs and AlxGa1−xAs in the pulse reactor

Abstract

Abstract The pulse reactor is a cyclic-operation low-pressure metalorganic vapour phase epitaxy (MOVPE) reactor in which in principle any binary, ternary, and quaternary multilayer device structure can be grown in a succession of a few thousands of “growth cycles”. In each cycle, of typical duration ≈1 s, growth proceeds from a low-pressure ( ≈1 mbar) mixture that contains the necessary growth species and which during the reaction is immobile with respect to the substrates. In one cycle, 1 to 50 atomic layers can be deposited. A theoretical description of the evolution of the growth rate in one cycle is presented. In one cycle the growth rate determining mechanism changes from kinetically to diffusion controlled. A cold-walled version of the pulse reactor is now operational and has been tested for GaAs-AlxGa1−xAs growth. Growth rate (up to 50 μm/h) and morphological qualities are comparable to conventional MOVPE. In the present reactor uniformly is typically ≈ 5% over a complete 2 inch wafer and can probably be improved easily.