High efficiency deposition of diamond film by hot filament chemical vapor deposition

A new designed reaction chamber with new relative distribution of filament and substrates has been adopted in order to increase the deposition area of diamond films and thus increase the deposition efficiency in conventional hot filament chemical vapor deposition (HFCVD) systems. The relatively small reaction chamber was cuboid shaped (50 x 25 x 25 mm(3)) and composed of molybdenum wafers. It was established in the vacuum chamber. A tungsten filament was hung up vertically in the center of the small chamber and parallel to the gas flow path. At the four inner sides of the reaction chamber, four Si(100) substrates (30 x 10 x 0.5 mm(3)) were installed to grow diamond films. The deposition results indicate that uniform diamond films can be obtained on the four substrates, and the film growth rate is the same at both ends of the substrates. The diamond film growth rate was about 1-2 mu m/h, which is similar to those of the conventional HFCVD method. Thus, the deposition area and efficiency can be increased four times in the case without the filament number, gas how rate, and power consumption.