Wide-Rrange Control of Crystallite Size and Its Orientation in Glow-Discharge Deposited µc-Si:H

Crystallite size and crystal-axis orientation have been widely controlled in glow-discharge deposited microcrystalline silicon (µc-Si:H) by setting a third electrode in a capacitively coupled glow-discharge system. Crystallite size of microcrystals has varied continuously from 80 A to 350 A in diameter as the substrate bias voltage is scanned from +100 V to -150 V when the third electrode is kept grounded. Strong preferential orientation to the (220) crystallographic axis of crystallite has also been observed when the positive bias voltage was applied to the substrate heated at 350°C. It has been demonstrated on the basis of mass spectrometric measurement that the crystallite size is strongly affected by the amount of ionic species impinging on the growing surface of µc-Si:H.