Date:
-
Location:
CP-137
Speaker(s) / Presenter(s):
Dr. Yujun Shi
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Dr. Yujun Shi of the University of Calgary will be presenting a seminar titled:
Gas-phase and Surface Chemistry in the Hot-wire Chemical Vapor Deposition Process of Silicon Carbide
Abstract: Hot-wire chemical vapor deposition (HWCVD) has received continued research interest as a powerful technique for the deposition of semiconductors, metal oxide nanoparticles, and polymer coatings. Extensive studies can be found on optimizing the process conditions and characterizing the properties of final products, however a lot of work remains to understand the reactions in the gas phase and on the wire/substrate surfaces for a complete understanding of the film growth mechanisms and for a rational and efficient improvement of the processes. Our group has studied the gas-phase reaction chemistry when using open-chain alkylsilane and cyclic silacyclobutane molecules, the two important type of single-source organosilicon precursors for silicon carbide formation. In this seminar, results will be presented on our investigation of the complex reaction chemistry of these two types of source gases using laser ionization mass spectrometric diagnostics in combination with isotope labeling and chemical trapping. In addition, the alloying of metal filaments, which serve as catalysts in HWCVD, will also be discussed. The nature of the alloys formed is closely linked to the gas-phase chemistry exhibited by the precursor gases. The phase changes in the alloying processes depend heavily on the interplay of Si/C diffusion into the wire and their evaporation from the wire surface.
Faculty Host: Dr. Dennis Clouthier
