Analysis of the Pyrolysis Products of Dimethyldichlorosilane in the Chemical Vapor Deposition of Silicon Carbide in Argon

A study of the products and reactions occurring during the chemical vapor deposition of silicon carbide from dimethyl‐dichlorosilane in argon is presented. Reaction conditions were as follows: 700° to 1100°C, a contact time of ∽1 min, and a pressure of 1 atm (∽0.1 MPa). At these conditions, the gases that formed were mainly methane, hydrogen, silicon tetrachloride, trichlorosilane, and methyltrichlorosilane. Hydrogen chloride might also be present, but was not determined. The silicon carbide solid that formed showed the presence of hydrogen and chlorine as impurities, which might degrade the silicon carbide properties. These impurities were eliminated slowly, even at 1100°C, forming hydrogen, trichlorosilane, and silicon tetrachloride.