Effects of Thermal Annealing on the Atomic Structure and the Residual Stress of Amorphous Carbon Films: A Molecular Dynamics Simulation

Kyung-Soo Kim, Seung-Cheol Lee, Kwang-Ryeol Lee, Pil-Ryung Cha,
 

Changes of atomic structure and residual stress of tetrahedral amorphous carbon (ta-C) films were investigated by molecular dynamics simulation. Annealing of ta-C film at 2000 K for 0.5 ns decreased the high level of residual stress of ta-C film up to 27 %. On the contrary, the mechanical property of the films, which is represented by sp³ bond ratio, was seldom changed. Only the 1.7 % decrease of sp³ ratio was obtained, which agreed well with experiment. The annealing affected the relaxation of the atomic configuration with high energy, which is referred to as the high-stress configuration of satellite peak found in radial distribution function. Since the short time annealing only affected the reduction of the residual stress, this method can be applied when one wants to reduce the residual stress with maintaining mechanical property.