Numerical analysis of injection level dependent effective lifetime on 125 mm undiffused lifetime samples

Effective minority carrier lifetime reduction at low injection levels is observed on 125 mm undiffused lifetime samples whose surfaces are under inversion due to field-effect passivation. With numerical analysis, we show that edge recombination is insufficient to account for this phenomenon on these samples. Between surface damage and asymmetric bulk lifetimes mechanisms that can account for the reduction, surface damage is confirmed to be more plausible. We demonstrate that the measured effective lifetime curves can be well reproduced assuming surface damage, a 700 nm thin layer with much lower bulk lifetimes, with numerical simulation.