Kinetic modeling of microscopic processes during electron cyclotron resonance microwave plasma-assisted molecular beam epitaxial growth of GaN/GaAs-based heterostructures

iReceived Microscopic growth processes associated with GaN/GaAs molecular beam epitaxy (MBE) are examined through the introduction of a first-order kinetic model. The model is applied to the resonance microwave plasma-assisted MBE (ECR-MBE) growth of a set of delta- GaNyAs1-y/GaAs strained-layer superlattices that consist of nitrided GaAs monolayers separated and that exhibit a strong decrease of y with increasing T over the range 540-580 degrees C. This y(T) dependence is quantitatively explained in terms of microscopic anion exchange, and thermally activated N surface-desorption and surface-segregation processes. N surface segregation is found to be significant during GaAs overgrowth of GaNyAs1-y layers at typical CaN ECR-MBE growth temperatures, with an estimated activation energy E(s) similar to 0.9 eV. The observed y(T) dependence is shown to result from a combination of N surface segregation/desorption processes. (C) 1996 American Institute of Physics.