STUDY OF SIO2-SI INTERFACES BY PHOTOCURRENT MEASUREMENTS

An experimental study is presented about surface recombination velocit y obtained from photocurrent measurements by the Elymat technique. Sur face recombination velocity has been studied as a function of process conditions (oxidation cycle, hydrogen annealing, cleaning procedures) with the aim to investigate how this parameter can be used for determi ning some properties of oxide-silicon interfaces. The data of surface recombination obtained from photocurrent measurements have the expecte d dependence on the oxidation cycle and on a H-2/N-2 post-oxidation an nealing, so we concluded that these data actually reflect the status o f the oxide-silicon interface. In addition, these data are shown to be affected by the cleanliness of the oxidation equipment, and they are unaffected by bulk properties of the oxide. By using these measurement s, we show that N2O treated interfaces have a better stability under b aking treatments than N, annealed interfaces. The dependence of surfac e recombination velocity on injection level can be modeled by analogy with bulk recombination by Shockley-Read-Hall recombination statistics . (C) 1997 Elsevier Science B.V.