Pre-breakdown in thin SiO2 films

The on-off fluctuations of the tunnel current in 5.6 nm SiO/sub 2/ films before dielectric breakdown are analyzed in detail. For this purpose, a low noise measurement system has been realized which allows detection of pre-breakdown phenomena and interruption of the stress before catastrophic failure occurs. A spectral analysis of these fluctuations is presented along with preliminary results of the experiments made possible, for the first time, by the new measurement system.