Mass Spectrometric Study of the Gas Phase During Chemical Vapor Deposition of Pyrolytic Carbon

Abstract

The pyrolysis of CH 4 , of C 3 H 8 and of the mixture 20C 3 H 8 /80CH 4 was investigated in a hot wall CVD reactor by mass spectrometry. Experiments were conducted as a function of temperature and of surface-to-volume (S/V) ratio of the substrate. The main by-products of the pyrolysis were identified and reaction mechanisms were proposed taking into account homogenous decomposition/formation reactions. Cyclic species are possibly involved in the formation mechanism of pyrocarbon.