基片偏压对ta-C薄膜结构和摩擦因数的影响

Effect of Substrate Bias on Structure and Friction Coefficient of Tetrahedral Amorphous Carbon Films Deposited by Filtered Cathodic Vacuum Arc

利用磁过滤阴极电弧技术,通过改变基片负偏压(0～500 V)制备四面体非晶碳(ta-C)薄膜,研究基片负偏压对ta-C薄膜结构和摩擦因数的影响。研究表明,基片负偏压对ta-C薄膜的sp3键含量有很大影响,当负偏压为200 V时,ta-C薄膜的sp3键含量为85%。在0～200 V范围内随着基片偏压的增大,表面粗糙度逐渐减小,在负偏压为200 V时,薄膜表面粗糙度最小,为0.18 nm左右;当负偏压超过200 V后,由于薄膜中石墨相增多,薄膜表面粗糙度将增大。随着基片偏压的逐渐增大,由于薄膜表面粗糙度的减小和在摩擦中石墨相自润滑层的形成,薄膜的摩擦因数大大降低,耐磨性提高。

Tetrahedral amorphous carbon（ta-C） films were deposited with technology of filtered cathode vacuum arc by changing the substrate negative bias from 0 to 500 V, and the effect of substrate bias on ta-C films structure and friction co- efficient was studied. The study results show that the fraction of the sp3 bonding in the ta-C films is affected by the sub- strate bias,and the sp3 fraction is about 85% when the substrate negative bias is at 200 V. Along with increasing of the substrate negative bias from 0 to 200 V, the surface roughness of the films is decreased gradually, and a minimum of about O. 18 nm reached at the substrate negative bias 200 V. However,when the substrate negative bias is more than 200 V, the surface roughness of the films is increased because of the increased graphite phase in the films. Because of decreasing at surface roughness and forming of graphite phase self-lubricating layer in the films, the friction coefficient of the films is de- creased greatly and the antiwear ability is improved along with gradual increasing of substrate negative bias.