In-Situ Infrared Spectroscopy of Hydrocarbons in a Pyrocarbon CVD Reactor

Abstract

Pyrocarbon film is synthesized by CVD method. The complex pyrolysis reactions in the gas phase cause the concentration distribution in the reactor. Since the precursor hydrocarbons which react into carbon determine the structure of the resulting film, the hydrocarbon distribution in the reactor should be elucidated for predicting and controlling the product film quality. In this study, the hydrocarbon distribution in a pyrocarbon CVD reactor was measured by infrared spectroscopy. Introducing an infrared beam into the tubular CVD reactor along the central axis of the tube, the infrared absorbance spectrum was measured with varying the diameter of the beam and the space time. By differentiating the measured absorbance both in radial and axial directions, the two-dimensional concentration distribution was obtained successfully.