A new technique for determining long-term TDDB acceleration parameters of thin gate oxides

Abstract

A new technique, the dual voltage versus time curve (V-t) integration technique, is presented as a much faster method to obtain time-dependent dielectric breakdown (TDDB) acceleration parameters (/spl alpha/ and /spl tau/) of ultrathin gate oxides compared to conventional long-term constant voltage stress tests. The technique uses V-t curves measured during highly accelerated constant or ramped current injection breakdown tests. It is demonstrated that the technique yields acceleration parameters that are statistically identical to values obtained from long-term constant voltage TDDB tests. In contrast to traditional TDDB tests, the proposed technique requires over an order of magnitude less testing time, a smaller sample size, and can be used during production monitoring.