MICROCRYSTALLINE SILICON THIN-FILMS PREPARED BY RF REACTIVE MAGNETRONSPUTTER-DEPOSITION

Hydrogenated microcrystalline silicon mu c-Si: Hi thin films with Cu a s a dopant material (about 2 wt.%) were deposited by RF planar magnetr on sputtering in an argon/hydrogen plasma. The composition and microst ructure of the films were analysed by SEM, ERD/RBS, X-ray diffraction and Raman spectroscopy. These techniques revealed a columnar film stru cture each column consisting of several small (nano) crystals with a l ateral dimension up to 100 Angstrom. The crystals are oriented, genera lly with the (111) plane parallel to the sample surface. The hydrogen content of the thin films is about 27-33 at. %. Low deposition rates a nd low sputter gas pressures favour crystallisation and grain growth. The behaviour can be understood in terms of the diffusion or relaxatio n length Lambda of the deposited Si-atoms.