MICRO-STRUCTURAL AND ELECTRICAL EVOLUTIONS OF BORON-DOPED MICROCRYSTALLINE SILICON THIN FILMS ON GLASS PREPARED BY VHF-PECVD

摘要

The evolution of micro-structural and electrical properties of the boron-doped microcrystalline silicon (μc-Si:H) films as film thickness accumulated in plasma enhanced chemical vapor deposition (PECVD) growth process were studied. The systematic study of micro-structural evolution of the films was obtained by field-emission scanning electronic microscopy (FE-SEM) and thin-film X-ray diffraction (TF-XRD) measurements with grazing (incident angles of 0.35°–5°) and normal (θ to 2θ) incidence. The crystallographic transition from the preferential orientation of Si(111) to (220) were observed by XRD, associated with the dramatic evolution of morphology and lateral grains observed by SEM. It is found that the carrier lifetime and conductivity increase as the film thickness increases. However, in the transition regime of preferential crystallographic orientation from Si(111) to Si(220) the electrical properties of μc-Si:H films exhibit different behaviors.