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In situ analysis of surface reactions during organometallic vapor phase epitaxy growth
Abstract
This study focuses on the reactions leading to the organometallic vapor-phase epitaxy of gallium nitride from trimethylgallium (TMGa) and ammonia and of gallium arsenide from TMGa and trimethylarsenic (TMAs). Organometallic vapor-phase epitaxy involves both homogeneous and heterogeneous reactions. This process is used to form epitaxial layers on semiconductor surfaces. The chemistry involved is complex and many of the intermediate species leading to the deposited crystalline material remain unresolved. Heterogeneous processes proved to have a primary effect on the decomposition of the reactants, and surface infrared emission spectroscopy was developed as a method to observe these species in situ. All the reactants were observed to be adsorbed on the surface during in situ runs. The surface was between 400 and 600$\sp\circ$C during these experiments, indicating chemisorption. Specifically, sorbed methyl groups were observed above 500$\sp\circ$C, indicating that both TMGa and TMAs decompose heterogeneously. It was also found that TMAs reacts directly with the hydrogen diluent and thus transports beneficial hydrogen to the surface.
Subject Area
Chemical engineering|Condensed matter physics
Recommended Citation
Mazzarese, David John, "In situ analysis of surface reactions during organometallic vapor phase epitaxy growth" (1993). Doctoral Dissertations Available from Proquest. AAI9329644.
https://scholarworks.umass.edu/dissertations/AAI9329644