SCALING OF DLC CHEMICAL VAPOR DEPOSITION METHOD WITH THE USE OF THE PLASMA CATHODE

Parameters of plasma generated in a large volume (0.34 m 3) chamber by pulsed injection of electrons (50 kHz, 10 ms) with 50-400 eV energy from the plasma generated by dc glow discharge in electrode system of the plasma cathode with grid stabilization (GPC) were investigated. Two GPC with a total electron emission current of 6 A were used in the study. The maximum current of a pulsed non-self-sustained discharge was limited by 15 A and the density of an ion current did not exceed 1 mA/cm 2 that provides high rate of diamond-like coatings (DLC) deposition at the temperatures excluding their overheating and graphitizing. Space non-uniformity of argon plasma density did not exceed 20 % in the area of ~ 400x400 mm 2 size. Results of tests of industrial-scale vacuum coater UVNIPA 1-002 completed with two GPCs are given. Voltage-current characteristics of the discharge in Ar + C 2H 2 gas mixture and dynamics of gas pressure in the processing chamber were investigated during the DLC deposition process. Optimum ratio of the discharge current and Ar + С 2Н 2 gas flow which ensures high microhardness of DLC (~ 20-35 GPa) and high rate of DLC deposition (~ 1 |im/h) was determined. Up to 10 at. % Ar and O are contained in DLC.