Fabrication of high quality polysilicon thin film on glass and its in situ real-time monitoring by spectroscopic ellipsometry

Polysilicon thin films, exhibiting both high crystallinity (100 vo1.%) and photoconductivity, were successfully fabricated on glass substrates at 360°C from fluorinated precursors SiFnHm (n+m⩽3). Furthermore, crystallinity around the interface region between glass and film was effectively improved by the layer-by-layer (LBL) technique wherein deposition of thin layer (~4 nm) and exposure to atomic hydrogen were alternately repeated. It is clarified by in situ real time spectroscopic ellipsometry that the main role of atomic hydrogen on crystallization is promotion of “grain growth” within the sub-surface of several nanometers thick beneath the growing surface in the case of growing poly-Si from fluorinated precursors