HIGH-EFFICIENCY DEPOSITION OF DIAMOND FILM BY HOT-FILAMENT CHEMICAL-VAPOR-DEPOSITION

A new designed reaction chamber with new relative distribution of fila ment and substrates has been adopted in order to increase the depositi on area of diamond films and thus increase the deposition efficiency i n 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 v acuum chamber. A tungsten filament was hung up vertically in the cente r 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 resu lts indicate that uniform diamond films can be obtained on the four su bstrates, and the film growth rate is the same at both ends of the sub strates. The diamond film growth rate was about 1-2 mu m/h, which is s imilar to those of the conventional HFCVD method. Thus, the deposition area and efficiency can be increased four times in the case without t he filament number, gas how rate, and power consumption.