Characterization and modeling of dark current, residual images, and the point-spread function in charge-coupled devices

The performance of modern scientific Charge-Coupled Devices (CCDS) has reached a point were even small noise sources are of major concern. The intent of this study is to further increase the understanding of how basic performance characteristics, like the spatial resolution or the dark current level, are influenced by internal parameters.; The first part of the study is devoted to the dark current in back-illuminated cameras. Dark current is caused by electrons that are thermally exited into the conduction band. These electrons are collected by the well of the CCD and add a false signal to the chip. We found that the occurrence of pixels with very high dark current, so called hot pixels, can be explained by high concentrations of mid gap impurities. An algorithm that automatically corrects for dark current is outlined. It uses a calibration protocol to characterize the image sensor for different temperatures. The hot pixels are then used as temperature indicators and predict the dark current of all pixels on the chip. The temperature dependence of the dark current of different pixels follows the Meyer-Neldel rule (MNR). We found that the MNR for dark current can be explained by taking into account two different sources of dark current: the diffusion and the depletion current. A general model for the MNR of a property, which is the sum of two thermally activated processes, is presented. It is also demonstrated that the current of a diode in forward bias shows MNR behavior due to shift from the ideal diode regime to the high injection regime.; Another effect investigated by this study is the occurrence of residual images. We present a model that quantitatively explains residual images by the presence of trapping sites in the depletion region.; Finally, an analytical model of the charge diffusion in the field-free region is presented. The model can be used to calculate the spatial resolution or point-spread function of back-illuminated sensors. A comparison with Monte-Carlo simulations and experimental data is used to determine the size of the field-free region of a back-illuminated chip.