Electrical and Mechanical Characteristics of Co-Doped and Ni-Doped Carbon Thin Films

抄録

To create conductive and wear-durable carbon thin films using metal doping, we deposited Co-doped and Ni-doped carbon thin films onto silicon substrates by RF sputtering. Then we evaluated the dopant concentrations, resistivity, scratch hardness, carbon sp² and sp³ bonding fractions, and the microscopic structure of the films. The resistivity of the Co-doped film remarkably decreased compared to that of non-doped carbon film when the dopant concentration was 1 at.% and it slightly decreased when the dopant concentration increased. The Ni-doped film resistivity decreased when the dopant concentration increased. The scratch hardness of the Co-doped and Ni-doped films was approximately equal to that of the non-doped film when the metal concentrations of the films were less than 6 and 5 at.%, respectively. The scratch hardness of the Co-doped film was degraded slightly as the dopant concentration became greater than 7 at.%. However, the scratch hardness of the Ni-doped film was significantly degraded when the dopant concentration was greater than 7 at.%. The Co-doped film with dopant concentration less than 12 at.% was most suitable from a practical perspective because of its low resistivity and high scratch hardness.