Correlation Between Soft Breakdown and Plasma Process Induced Damage

The correlations between soft breakdown (SB) and plasma process induced damage of devices with ultra-thin gate oxides were presented. A stress and test methodology was proposed to analyze SB due to sudden decrease in gate voltage during a constant current stress. The voltage used for measurements was kept small to avoid Fowler-Nordheim tunneling. The analysis suggested the dependence of cummulative failure distribution on antenna ratio. It was found that the use of low voltages caused more localized damage and increased the chance trigger SB spot into conduction.