Optical second‐harmonic generation study of charge trapping dynamics in HfO2/SiO2 films on Si(100)

Electrostatic-Field-Induced Second Harmonic (EFISH) generation is used to characterize laser-induced charge trapping dynamics in thin HfO2 films deposited on chemically oxidized P-type Si(100) substrates. We monitor EFISH generation as a function of time, HfO2 thickness and post-deposition annealing (PDA). In as-deposited films, the results show that electrons and holes are injected and trapped in comparable amounts, but on different time scales. In annealed films, electron dynamics dominate at all times. Quantitative details depend on film thickness. These results show that time-dependent EFISH generation can provide an in situ, non-destructive diagnostic of charge trapping in thin high-k gate dielectric films. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)