Deposition of Homogeneous Amorphous Carbon Film at High Growth Rates by Vacuum Arc Deposition

Abstract

Although vacuum arc deposition can deposit amorphous carbon (a-C) film at high growth rates, the problem is that it leads numerous droplets than other PVD. Proposed methods for decreasing droplets, such as shield plate and magnetic filter, can actually decrease droplets, however they reduce growth rate. This study focuses on deposition of a-C films by vacuum arc deposition to achieve both higher growth rates and homogeneity of a-C films by decreasing droplets. It is necessary to control the vaporizing process of solid carbon target by improving discharge conditions for both higher growth rates and fewer droplets. Deposition of a-C film with low density of droplets at high growth rates was attempted by optimizing discharge voltage, electric charge and the structure of arc discharge unit. The optimized conditions, such as higher discharge voltages, larger electric charges and shorter distances between cathode spot and anode edge, decreased the number density of droplets per film thickness. The a-C film deposited under the optimized condition had the number density of droplets of 4.2/mm2·nm at the growth rate of 3.5 nm/count. XPS analysis showed that deposited a-C films had sp3 ratio of about 80%, therefore its density was estimated to be approximately 3.0g/cm3.