Growth of microcrystalline silicon using the layer-by-layer technique at various plasma excitation frequencies

Microcrystalline silicon (mu c-Si:H) was deposited with the layer-by-layer technique at various plasma excitation frequencies. For hydrogen treatment times (t(H)) less than a critical time (t(C)), the films are amorphous and the thickness decreases Linearly with t(H). For t(H) larger than t(C) microcrystalline growth was observed, while the thickness remained constant. The range of t(H) for microcrystalline growth and constant film thickness increased with the plasma excitation frequency. Transmission electron microscopy of films with comparable thickness show that the excitation frequency affects the structure of the layer-by-layer films. For low frequencies, amorphous growth is observed; for intermediate and high frequencies, the structure is crystalline with variations in density and crystallite sizes. (C) 1998 Elsevier Science B.V. All rights reserved.