Characterization of individual electron traps in amorphous Si by telegraph noise spectroscopy

Abstract
We have used telegraph noise spectroscopy to study the properties of individual localized electron traps of a particular type in thin layers (t<∼6 nm) of rf sputtered amorphous Si and amorphous Si:H. The results indicate that these traps have bistable ionic configurations: The trapping kinetics are dominated by transitions between two different ionic configurations with an associated change in trapped charge. Above ∼20 K, configurational transitions are by thermally activated hopping; below 20 K, transitions appear to be induced by zero-point oscillations.