Numerical evaluation of growth conditions of GaN-based LEDs in multiwafer MOCVD reactor

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In this paper, numerical evaluation of growth conditions of GaN in multiwafer planetary MOCVD reactor was carried out. The growth of GaN films using TMGa as a precursor, hydrogen and nitrogen as carrier gas was investigated. For the mathematical solution of the fluid flow, temperature and concentration fields, the commercialized computational fluid dynamics (CFD) based solver-Ansys-FLUENT was utilized. A 2-D model utilizing axisymmetric mode to simulate the gas flow in a MOCVD has been developed. The model takes into account the momentum conservation equation coupled with heat transfer and mass transport of the chemical species. The effects of substrate temperature, reactor pressure, rotation speed of the susceptor, mass fraction of carrier gas, and total flow on the gas flow field, temperature field, and species distribution were analyzed and discussed. It was found that the growth temperature plays an important factor in the growth rate and layer thickness uniformity. The rotation speed of susceptor has no obvious effect on the growth rate, but the uniformity of layer thickness increase with the rotation speed at first and then have a turning point with the continuous increase of rotation speed. The reactor pressure, mass fraction of carrier gas and total flow also are key issues to obtain desired growth rate of GaN film. In a world, the fundamental numerical simulation offers reliable preliminary determination of experimental conditions and facilitate the optimization process of MOCVD design in a reduced time and cost.

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Journal: TechConnect Briefs
Volume: 2, Nanotechnology 2011: Electronics, Devices, Fabrication, MEMS, Fluidics and Computational
Published: June 13, 2011
Pages: 655 - 658
Industry sector: Advanced Materials & Manufacturing
Topic: Informatics, Modeling & Simulation
ISBN: 978-1-4398-7139-3