BREAKDOWN CHARACTERISTICS OF ULTRA-THIN GATE OXIDES FOLLOWING FIELD AND TEMPERATURE STRESSES

Here, we investigate the reliability of silicon dioxide layers for two different thickness values (8 and 4.5 nm). The time to breakdown (t(b d)) was determined using constant voltage stress (CVS) under different experimental conditions. The first set of data, which was used to det ermine the activation energy, corresponds to t(bd) at fixed electric f ield and different temperatures. The second set of data was obtained a t fixed temperature and increasing electric field and was used to dete rmine the field acceleration factor. It is shown that both activation energy and field acceleration factor can be used to determine the life time and the reliability of the gate oxide. For the thinner oxide, we observed a different behavior. In fact, during the CVS of the 4.5 nm t hick oxide a quasi-breakdown phenomenon was found. The light emission which occurred during this phenomenon was investigated. (C) 1997 Publi shed by Elsevier Science Ltd.