Paper presented at ICMCTF 2011.
“In this presentation I will address the different roles atomic hydrogen and ions play in the synthesis of thin amorphous and crystalline materials. In particular I will address the role of atomic H during the growth of amorphous and microcrystalline silicon as determined from in situ studies using optical emission spectroscopy (to monitor the hydrogen flux) and evanscent wave cavity ring down spectroscopy to measure the subsurface defect density. Controlled monoenergetic ion energy distribution functions, by means of pulsed biasing scheme, will be used to illustrate the different roles of ion flux and ion energy in the densification of hydrogenated amorphous silicon. Moreover during ion bombardment studies on thin film amorphous silicon films an ion induced Staebler-Wronski effect was observed. It will be demonstrated that defects in this case are created by UV photon generation as a result of electron-ion recombination on the surface and is not due to ion collision cascade effects as normally assumed. In addition the role of H in ZnO:Al electronic transport properties will be addressed.”