Partition noise in CCD signal detection

Reset noise in CCD signal charge detection has been analyzed experimentally and theoretically. From the reset noise measurement experiment, it has been inferred that reset noise consists of sensing capacitance Cs dependent part and effective reset channel length L dependent part. Conventional reset noise theory, where the Johnson noise in reset MOS channel was regarded as the only reset noise source, agrees with the Cs dependent part of measured reset noise. However, it cannot explain the L dependent part. To explain the L dependence, the authors propose "partition noise" caused by carrier partition in the reset MOS channel. Partition noise has been analyzed by the unique technique of solving the one-dimensional diffusion equation. As a result, a reset channel capacitance dependent characteristic for partition noise has been derived, which agrees with the L dependent part for measured reset noise. Consequently, in addition to Johnson noise, partition noise is found to be a noise source in CCD signal detection.