Barrier lowering in short-channel CCD´s

In a two-phase overlapping CCD structure, the potential barrier height in the gap between the two storage gates decreases as the gap length is reduced due to fringing field effects. The barrier lowering limits the charge handling capacity in short-channel CCD´s. A two-dimensional model is developed to calculate the barrier height for the various gap lengths. A simple measurement technique is developed to obtain experimental data using submicrometer structures and the data is compared with the model. Several important process parameters relating to the barrier lowering are investigated for design consideration.