Nanoscale Manipulation of Tetrahedral Amorphous Carbon Films

Churl Seung Lee, Tae-Young Kim, Kwang Ryeol Lee, and Ki Hyun Yoon
 

The outstanding mechanical, chemical and tribological properties of tetrahedral amorphous carbon (ta-C) film have attracted much attention. For a wider variety of application, a great effort should be focused on the nanoscale structure control. In the presented work, we have adopted a novel technique for nanoscale manipulation of ta-C films; incorporating nano Ni dots at the interface between the ta-C film and the substrate. For Ni dot pretreatment, the Ni thin film was deposited and annealed prior to the ta-C films deposition. TEM and Raman spectrum analysis shows that the nano Ni dots at the interface between the film and the substrate results in nanoscale graphitic phase embedded in hard ta-C matrix. Mechanical and electrical properties were strongly dependent on the changes of the Ni-induced second phase. The reduction of mechanical properties and electrical resistivity with increasing the size of Ni dots could be understood in the view point of the local increase of sp² bonds in hard ta-C matrix.