Deposition and characterization of a- and μc-Si: H thin films by ICP-CVD system with internal antennas

The plasma of an ICP-CVD system attached with four internal antennas was characterized using a plasma probe and an optical emission spectrometer (OES). Plasma density and averaged electron temperature were examined as functions of RF power input and working pressure. It is found that the averaged electron temperature would decrease with the increase of working pressure and slightly decrease with the increase of RF power. The films' crystallinity (X_c) increases with the decrease of working pressure, and with the increase of power input. At low pressure, X_c is related to electron temperature. When working pressure is fixed, the electron temperature is not affected by power input. In this case, X_c is related to the OES intensity of SiH*which is proportional to H*. For a-Si:H, the deposition rate decreases with the increase of working pressure and slightly increase with the increase of power. For μc-Si:H, the deposition rate increases with the increase of power and pressure. The quantum efficiency of the film is related to the mechanisms of forming crystalline structure, which, in turn, may reduce defect density. No relationship between I_Hα* and film's growth rate or X_c can be identified in this study.