Researches on uniformity of diamond-like carbon films deposited on inner surface of long and slender quartz glass tube by enhanced glow discharge plasma immersion ion implantation and deposition

Enhanced glow discharge plasma immersion ion implantation and deposition (EGD-PIII&D) has been successfully used for depositing diamond-like carbon (DLC) on the inner surface of the quartz glass tube with an inner diameter as small as 0.9 mm and aspect ratios of over 100. And the uniformity is a key problem for the DLC films deposited on the inner surface. By changing the C2H2 flow rate and negative voltage, the effects of the gas flow rate and voltage on the uniformity of the DLC films deposited on the inner surface of the quartz glass tube are experimentally examined. The electron-neutral collision frequency, νe, is used to qualitatively analyze the mechanism of uniformizing DLC films. The results reveal that uniform DLC films may be obtained by balancing both the gas flow rate and the negative voltage.