ELECTRICAL AND THERMAL TRANSIENT DURING DIELECTRIC-BREAKDOWN OF THIN OXIDES IN METAL-SIO2-SILICON CAPACITORS

The dielectric breakdown of gate oxide layers with thickness of 35 and 9.3 nm in metal-oxide-semiconductor capacitors with a n(+) polycrysta lline Si/SiO2/n(-) Si stack was investigated. Breakdown was characteri zed in a particular circuit configuration by following the time evolut ion of voltage, current, and power through the capacitor with a time r esolution of the order of 2 ns. A detailed morphological characterizat ion of the damaged samples by emission and transmission electron micro scopy is shown and discussed. The results of the morphological analysi s and of the electrical measurements are quantitatively discussed by s imulating, through heat-flow calculations, the time evolution of the t emperature in the regions interested to the breakdown phenomenon. (C) 1998 American Institute of Physics.