COUPLED ELECTRON-HOLE DYNAMICS AT THE SI SIO2 INTERFACE/

We report a new and surprising enhancement of the electric field at th e Si/SiO2 interface following the cessation of intense pulsed near-inf rared radiation. The phenomenon, measured by optical second-harmonic g eneration, occurs only for photon energies and oxide film thickness th at exceed respective thresholds. We attribute the new effect to multip hoton hole injection into the oxide and to an asymmetry in electron an d hole dynamics, in particular to distinctly different trapping and de trapping processes.