Rf Plasma Discharge Preparation Dlc / Mo-dlc Film Properties

Diamond-like carbon (DLC) films have many unique properties such as high hardness, low friction coefficient, high electrical resistivity and have received extensive interest. However, the films have some intrinsic disadvantages: high compressive stress, poor thermal stability and poor adhesive properties with many substrates, for example. In order to improve these properties of DLC films, metal doped DLC films have been becoming an important topic of people's study.In this article, Diamond-like carbon (DLC) films were prepared with CH4-Ar using capacitively coupled plasma enhanced chemical vapor deposition method driven by dual-frequency of 40.68 MHz and 13.56 MHz in combination on silicon and BK7 glass substrates. We investigated the influence of plasma discharge parameters such as high frequency source power, low frequency source self-bias voltage, pressure, flow rate ratio on the properties and structure of deposited films. Also, by using high pure graphite and molybdenum as targets and Ar as source gas, we used radio frequency magnetron sputtering technology to deposit Mo doped DLC films on silicon and sodium chloride substrates, and the effect of substrate temperature on the structure of films was also discussed.We studied the properties and structure of the deposited films using profilemeter, UV-Vis-NIR spectrophotometer, Raman, AFM, XPS and TEM. The results show that the deposition rate increases with the increase of high frequency source power and low frequency source self-bias voltage; the optical band shows opposite trend. Raman measurements indicate that the deposited films have maximal sp3 content with applied negative self-bias voltage of -150 V, high frequency source power causes a continuous increase in sp2 content. The measurement of AFM shows that the surface of the deposited films under ion-bombardment becomes smoother than those with non-intended self-bias voltage. The measurement of XPS shows the Mo doped DLC films contain C, Mo and O elements, high temperature is benefit for the formation of C-Mo bond, which is also confirmed by the TEM observation.