An Analytical Expression for Charge Collection Probability From Within a U-Shaped Junction Well

The analytical expression for the charge collection probability within a U-shaped junction well is derived in this paper. The U-shaped junction well is a common feature found in most integrated circuits. The charge collection probability is the probability that the generated carrier will be collected at the charge-collecting junction. The availability of an analytical expression is expected to facilitate the study and development of the electron-beam-induced current technique and devices that share the same operating principle, e.g., the solar cell. The newly derived analytical expression is expected to avoid the computational difficulties and problems encountered using the currently available analytical expression. The charge collection probability profiles that were generated using a semiconductor device simulator program were used to verify the analytical profiles that were computed using the newly derived analytical expression. Good agreement was found. The junction depth, junction width, diffusion length, and depth of the generation volume were varied, and their effects were studied.