Investigation On C And Si_1-xC_x Films Deposited By Radio-frequency Or Very-high-frequency Magnetron Sputtering

As the important carbon-based thin films, the carbon and Si C thin films have attracted much attention recently because of their unique applications. The thin(< 30 nm) and ultrathin(< 2nm) a-C films are of particular interest as protective overcoats in several leading technologies such as magnetic storage devices and microelectromechanical systems. For this application, the a-C films with high hardness, low friction and very thin thickness are needed. Because the mechanical properties depend on the stronger σ bonds in the films, the sp3 contents in the a-C films should be increased as higher as possible. In additional, the Si-rich silicon carbide(Si1-x Cx) thin films have also attracted much attention because the Si-rich Si1-x Cx thin films can be used as a matrix material to host the Si nanocrystals(Si-NCs) for the photovoltaic applications and to self-aggregate the Si quantum dots(Si-QDs) for the optoelectronic devices.This thesis studies the deposition characteristics, structure and property of the thin C films deposited at the sputtering frequency of 60 MHz, 2MHz, 13.56 MHz and 27.12 MHz as well as the sputtering power from 100 W to 250 W, and the deposition characteristics, structure and property of the Si1-x Cx thin films deposited at the sputtering frequency of 2MHz, 13.56 MHz and 27.12 MHz as well as the sputtering power from 50 W to 250 W.For the a-C films prepared by the 60 MHz VHF magnetron sputtering, the surface morphology analysis by AFM shows that the a-C films have a very flat and smooth surface with a lower average mean roughness. The bonding properties analysis by FTIR shows that the a-C films have more sp3 contents. The thickness measurement by SE shows that the a-C films have a lower growth rate(0.42 – 0.97 nm/min). These features are thought to relate to the higher ions energy and the lower ions flux of the 60 MHz VHF sputtering. Therefore, the 60 MHz VHF sputtering is more suitable for the preparation of ultrathin a-C films with more sp3 contents.For the the deposition of Si-rich Si1-x Cx thin films, the results show that the driving frequency and sputtering power have greatly influence on the films compositions. At the driving frequency of 2 MHz, the Si-rich films with silicon fraction 1-x ranges 0.87 to 0.57 are deposited in the power range of 50 to 200 W. At the driving frequency of 13.56 MHz, the Si-rich films with silicon fraction 1-x ranges 0.83 to 0.57 are deposited in the power range of 50 to 250 W. At the driving frequency of 27.12 MHz, the Si-rich films with silicon fraction 1-x ranges 0.90 to 0.60 are deposited in the power range of 50 to 200 W. Therefore, the control of ions energy by changing the driving frequency(2 MHz, 13.56 MHz and 27.12 MHz) and sputtering power is a possible way to deposit the Si-rich Si1-x Cx thin films.