Laser techniques for studying chemical vapor deposition

Our work, a coordinated program of experimental and theoretical research in the funda-mental mechanisms of CVD, illustrates the application of laser techniques to the understandingof a CVD system. We have used a number of laser-based techniques to probe C\TD systems aiidhave compared our measurements with predictions from computer models, primarily for thesilane CVD system. The silane CVD model solves the two-dimensional, steady-state bouiidarylayer equations of fluid flow coupled to 26 elementary chemical reactions describing the thermaldecomposition of silane and the subsequent reactions of intermediate species that result in thedeposition of a silicon film. A detailed description of this model can be foumid elsewhiere.13Iii a horizontal channel-flow reactor, we have used pulsed UV laser Ran1all spectroscopy tomeasure gas temperatures and silane number density as a function of position in the reactor,temperature and gas coniposition.4 We also used laser-induced fluorescence spectroscopy (