Gamma induced dose fluctuations in a charge injection device

Spatial fluctuations in absorbed dose became important as device dimensions are scaled downward and the number of elements on a single chip increased. Furthermore, the extreme events in the distribution could determine the satisfactory operation of the array. The large sample size available in a charge injection device (CID) has made it possible, for the first time, to compare experimental results for gamma-induced dose fluctuations with theoretical calculations of extreme value distributions. The agreement between theory and experiment is excellent. In order to predict correctly the variance in the dose distribution from the basic model for solid-state imagers, it is found to be necessary in the case of a CID to include a term for carrier diffusion.>