AVS 51st International Symposium
    Thin Films Friday Sessions
       Session TF-FrM

Paper TF-FrM8
Real-time Optical Monitoring of Ammonia Decomposition Kinetics in InN Vapor Phase Epitaxy at Elevated Pressures

Friday, November 19, 2004, 10:40 am, Room 303C

Session: In-Situ/Ex-Situ & Real-Time Monitoring
Presenter: N. Dietz, Georgia State University
Authors: N. Dietz, Georgia State University
M. Strassburg, Georgia State University
V. Woods, Georgia State University
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Understanding the decomposition kinetics of the chemical precursors involved in nucleation and thin film growth processes is crucial for controlling the growth process. The growth of emerging materials heterostructures such as InN and related alloys requires deposition methods operating at elevated vapor densities due to the high thermal decomposition pressure in these materials. High nitrogen pressure has been demonstrated to suppress thermal decomposition of InN, but has so far not been explored in chemical vapor deposition experiments. The extension of chemical vapor deposition (CVD) to elevated pressure opens an avenue for retaining stoichiometric single phase surface composition for materials that are characterized by large thermal decomposition pressures at optimum processing temperatures. In this contribution we present research results on the decomposition kinetics of ammonia in the laminar flow regime of a high-pressure flow channel reactor. Real-time optical UV absorption and fluorescence spectroscopy has been applied to study the gas phase chemistry as function of flow, pressure and temperature. Data are presented for the optical methods of real-time process monitoring to analyze the decomposition process as well as the initial stages of InN heteroepitaxy.