DIAMOND FILM DEPOSITION BY DOWNSTREAM DC GLOW-DISCHARGE PLASMA CHEMICAL-VAPOR-DEPOSITION

A new d.c. glow discharge chemical vapour deposition (CVD) method was developed for diamond film (DF) deposition onto insulator substrates. This method uses ordinary d.c. plasma CVD equipment, but the anode sys tem was modified both to insulate the substrate holder from the anode and to set the substrate downstream of the plasma. This is achieved by two methods. First, the anode was made from the tungsten grid and the insulated substrate was placed under the grid and out of the discharg e area. Second, the anode was made from the thick-wall molibden tube a nd the substrates were placed on the insulator inside the tube, The ex periments were carried out under a hydrogen pressure of 50-150 Torr an d methane concentration of 1%-2%. The substrates (Mo or Si) were set o n the silica substrate holder. The temperature was approximately 1000- degrees-C. Diamond films were grown by both methods. Scanning electron microscopy, cathodoluminescence microscopy and spectroscopy, Raman sc attering and X-ray diffractometry were used to study and compare the d iamond films.