AVS 45th International Symposium
    Selected Energy Epitaxy Topical Conference Wednesday Sessions
       Session SE-WeA

Paper SE-WeA4
Gas-Phase Diagnostics for Wide Bandgap Semiconductor Development

Wednesday, November 4, 1998, 3:00 pm, Room 327

Session: Novel Sources for Selected Energy Growth
Presenter: D.G. Fletcher, NASA Ames Research Center
Authors: D.G. Fletcher, NASA Ames Research Center
G.A. Raiche, NASA Ames Research Center
Correspondent: Click to Email
Efforts to develop commercially viable wide bandgap semiconductors can be aided considerably by a characterization of the atomic beam. For arcjet devices used for nitride epitaxy, this involves determining the thermochemical state of a partially dissociated nitrogen flow. Since arcjet flows of nitrogen are also used in the development of thermal protection systems for aerospace applications, laser-spectroscopic techniques have been developed for flow characterization, and this has been driven by the need to relate test results to the flight environment. Recently, two-photon laser-induced fluorescence of ground-state atomic nitrogen has been used to determine the degree of dissociation and the enthalpy distribution in a large scale arcjet facility.@footnote 1@ Based on observations from these experiments and the similarities between the arcjet devices used in nitride epitaxy and aerospace materials testing, diagnostic strategies are proposed to establish the link between electronic state populations and nitride material growth. The paper will include a discussion of recent, relevant experimental results for ground state atomic nitrogen, and will report on progress made in developing laser-diagnostic strategies for determining the populations of the two low-lying, metastable doublet states of atomic nitrogen. @FootnoteText@ @footnote 1@D.G. Fletcher "Arcjet Flow Properties Determined from Laser-Induced Fluorescence of Atomic Nitrogen", AIAA Paper No. 98-0205, Reno, NV, January, 1998.