A controlled atmosphere tube furnace was designed for thermal CVD

High quality materials were used for the fabrication of hi-tech tube furnace. The furnace was especially suitable for thermal Chemical Vapor Deposition (CVD). High density alumina tube was used for the fabrication of furnace. The tube furnace was found to have three different temperature zones with maximum temperature at central zone was found to be 650 degrees C. The flexible heating tape with capacity of 760 degrees C was wrapped on the tube. To minimize the heat losses, asbestos and glass wool were used on heating tape. The temperature of the tube furnace was controlled by a digital temperature controller had accuracy of +/- 1 degrees C. Methanol was taken as the representative of hydrocarbon sources, to give thin film of carbon. The a-C: H structure was investigated by conventional techniques using optical microscopy, FT-IR and SEM.