Title :
Modeling Nonlinear Dark Current Behavior in CCDs
Author :
Dunlap, Justin C. ; Blouke, Morley M. ; Bodegom, Erik ; Widenhorn, Ralf
Author_Institution :
Portland State Univ., Portland, OR, USA
fDate :
4/1/2012 12:00:00 AM
Abstract :
A model explaining nonlinear time dependence of pixels in charge-coupled device (CCD) pixels is presented. The model describes the movement of the pixel´s depletion edge based on varying quantities of signal charge. Dynamic depletion edges will affect dark current collected by pixels with impurities located in the region of movement of the edge. The model attempts to address nonlinear behavior of dark current with respect to exposure time well below the saturation level seen in some CCD imagers. Modeling an imager by giving pixels varying number of impurities and depths of those impurities, assuming a uniform distribution, leads to characteristic behavior observed in the imagers.
Keywords :
CCD image sensors; CCD imagers; charge-coupled device pixels depletion edge; dynamic depletion edge; edge movement; nonlinear dark current behavior modeling; nonlinear time dependence; saturation level; signal charge; Charge coupled devices; Dark current; Data models; Equations; Image edge detection; Impurities; Silicon; Charge-coupled devices (CCDs); dark current; depletion edge; exposure time nonlinearity; impurities; model;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2012.2183000