Statistical characterization of current paths in narrow poly-Si channels

A statistical evaluation of current-voltage characteristics in small-size vertical poly-Si channels is used to study the poly-Si conduction properties and defects. Three poly-Si process options are considered. It is shown how defects and grain boundaries lead to percolation current paths, modulated by electron charging. Low mobility in microcrystalline-Si can be exchanged for higher mobility in large-grain poly-Si, at the expense of larger variability.