Characterization of dark current in CCD imagers

Dark current in CCD imagers is often the largest noise source. It is expected to be an increasingly serious problem as device dimensions are scaled. For dense image arrays, surface states along the oxide interface of the channel-stop sidewalls constitute a major source of dark current because the sidewall scales as a perimeter. Diagnostics are required to understand the origin of generation from channel stops and for process optimization. We present novel analytical and experimental methods for characterizing dark current in CCD devices based on a two-dimensional extension of the gated-diode technique.