Time-dependent dielectric breakdown of intrinsic SiO/sub 2/ films under dynamic stress

We present time-dependent dielectric breakdown (TDDB) characteristics for 9, 15, and 22 nm silicon dioxide films stressed under DC, unipolar, and bipolar pulsed bias conditions. Our results indicate that the increased lifetime observed under pulsed stress conditions diminishes as the stress electric field and oxide thickness are reduced. TDDB data under pulse bias conditions exhibit similar field and temperature dependencies as under static stress. C-V measurements indicate that lifetime enhancement only occurs for electric fields and thickness where charge trapping is significant.