Time-resolved layer thickness behavior of microcrystalline and amorphous silicon samples after switching on a hydrogen/silane VHF plasma

In the course of deposition and etch experiments – (a) on blank borosilicate glass substrates, (b) on borosilicate glass substrates coated with thin amorphous or microcrystalline films (`precoated substratesʹ), (c) `layer-by-layer (Lbl) experimentsʹ – the film thickness was measured in situ. Varying `seedingʹ times – up to ∼2000 s for (SiH4/(SiH4+H2))=1.5% and substrate temperature TS=180 °C on the blank substrates were detected, before a continuous growth started. Using the Lbl technique, high crystalline silicon layers (up to 70% Raman crystallinity) were reached. The experimental results will be compared with results of a simple 3D-simulation of the μc-Si growth process and will be discussed in context with the favored growth models for microcrystalline silicon (`diffusion modelʹ, `etching modelʹ, `growth zone modelʹ).