Charge Funneling in N- and P-Type Si Substrates

Enhanced charge collection via funneling may increase the vulnerability of integrated circuits to single particle induced upsets or errors. In this paper, measurements of the enhanced charge collection for diffused p+-n and n+-p junctions are compared for substrates of comparable resistivities and doping densities. Charge collection measurements on MOS capacitors are also presented. A simple phenomenological model of the charge funneling effect is developed based on an effective funnel length and is compared with the experimental results.