In-depth resolution for LBIC technique by two-photon absorption

A detailed study of the in-depth dependence of the laser-beam-induced current (LBIC) technique by sub-bandgap two-photon absorption (TPA) has been carried out in this paper. The strong focal dependence mechanism for TPA has been demonstrated by our studies through comparing the TPA technique with traditional single-photon-absorption-based ones. Dependence of the TPA-induced single-event transient response in linear integrated circuits on depth and position is investigated. Our results illustrate an interesting in-depth resolution for the TPA technique, which enables three-dimensional imaging of charge-collecting volumes through the backside of integrated circuits.