화학공학소재연구정보센터
Applied Surface Science, Vol.257, No.10, 4738-4742, 2011
Structure and hardness of a-C:H films prepared by middle frequency plasma chemical vapor deposition
a-C:H films were prepared by middle frequency plasma chemical vapor deposition (MF-PCVD) on silicon substrates from two hydrocarbon source gases, CH4 and a mixture of C2H2 + H-2, at varying bias voltage amplitudes. Raman spectroscopy shows that the structure of the a-C:H films deposited from these two precursors is different. For the films deposited from CH4, the G peak position around 1520cm(-1) and the small intensity ratio of D peak to G peak (I(D)/I(G)) indicate that the C-C sp(3) fraction in this film is about 20 at.%. These films are diamond-like a-C:H films. For the films deposited from C2H2 + H-2, the Raman results indicate that their structure is close to graphite-like amorphous carbon. The hardness and elastic modulus of the films deposited from CH4 increase with increasing bias voltage, while a decrease of hardness and elastic modulus of the films deposited from a mixture of C2H2 + H-2 with increasing bias voltage is observed. Crown Copyright (C) 2011 Published by Elsevier B. V. All rights reserved.