Electrical characterization of a-SiOx : H produced by plasma immersion ionimplantation

The plasma immersion ion implantation technique was used to implant oxygen into a-Si:H films, from very low doses to high doses, in order to explore t he alloying effect of oxygen in a-Si:H. From the electrical characterizatio n of the synthesized a-SiOx:H films, it was found that oxygen has a very st rong alloying effect in a-Si:H and that the band gap of a-SiOx:H or the bar rier height of a metal/a-SiOx:H contact was modified by the oxygen implanta tion. The a-SiOx:H films investigated have an effective band gap of 1.8-2.3 eV, which is optimum for some industrial applications of amorphous semicon ductors. However, because of the radiation defects, the conduction mechanis m of these a-SiOx:H films is dominated by Frenkel-Poole conduction. (C) 199 9 Elsevier Science Ltd. All rights reserved.