Applied Science and Convergence Technology 1999; 8(3-2): 346-352
Published online August 1, 1999
Copyright © The Korean Vacuum Society.
Seong-Hwa Kim,Kwang-Ryeol Lee,Kwang Yong Eun
Diamond-like carbon (DLC) films were deposited by using end hall type ion gun. Benzene gas was used for the generation of carbon ions. In order to systematically control the ion energy, we applied to the substrate DC, pulsed DC or 250 ㎑ medium frequency bias ranging from -100 to -800 V. We investigated the deposition behaviors depending on the type of the bias voltage, and the structure and properties of the films for various bias voltages. Without applying the bias voltage, DLC films of superior mechanical properties of hardness 39±4 ㎬ and elastic modulus 290±50 ㎬ (2 to 6 times better than those of the films deposited by plasma assisted CVD method) could be obtained. Deposition rate was much higher than when using Kaufman type ion source, which results from higher ion beam current of end hall type ion gun. The mechanical properties and atomic bond structure were independent of the bias voltage type but intimately related with the magnitude of the bias voltage. With increasing the negative bias voltage, the structure of the films changed to graphitic one resulting in decreased content of three dimensional inter-links. Degradation of the mechanical properties with increasing bias voltage could be thus understood in terms of the content of three dimensional inter-links.