Effects of ion bombardment on microcrystalline silicon growth by inductively coupled plasma assistant magnetron sputtering

Hydrogenated microcrystalline silicon(c-Si:H) thin films were deposited by inductively coupled plasma assistant magnetron sputtering(ICP-MS) in an Ar-H 2 gas mixture.The role of ion bombardment in the growth of c-Si:H films was studied with increasing negative bias voltages on the substrate holder from 0 to 100 V.Raman scattering,X-ray diffraction(XRD),Fourier transform infrared(FTIR) spectroscopy and transmission electron microscopy(TEM) were performed to investigate the microstructure changes of deposited Si films.Raman scattering showed that the high energy ion bombardment resulted in crystalline degradation of Si films.The XRD results showed the decrease and even elimination of preferential growth orientation of crystalline Si films with ion bombardment energy increase.The SiH bonding configuration changes and the increase of bonded hydrogen concentration were determined with the analysis of FTIR spectra.Furthermore,the dramatic evolution of cross-sectional morphology of Si thin films was detected by TEM observation.