Abstract
The relations between process parameters for hydrogenated microcrystalline silicon (μc-Si:H) thin films and properties of deposited films are demonstrated in this thesis. μc-Si:H thin films are prepared by plasma-enhanced chemical vapor deposition (PECVD) with very high frequency (VHF) at 27.12 MHz. Several process parameters can influence properties of deposited films and also be studied in our results, as the hydrogen dilution ratio, the VHF-power, the pressure and the electrode gap. The glow of the plasma associated with properties of deposited films is detected by optical emission spectroscopy (OES). The spectral lines for our interest are the SiH* (412.8 nm), the Hα (656.2 nm), the Hβ (486.2 nm) and the H2 Fulcher (600-630 nm). OES measurement results are shown in the types of OES-ratios (Hα/ SiH*, Hβ/ SiH*) to analyze the connection with properties of deposited films. The degree of crystalline (Xc) as the material property is obtained by Raman system. The photosensitivity as the electrical property is detected by solar simulator. In our case, the correlations between process parameters for μc-Si:H thin films and properties of deposited films can be proved that the variations of OES-ratios at different deposition parameters are similar with the degree of crystalline but opposite to the photosensitivity. From these results, we can predict properties of deposited films from measurement results of OES.