An accurate extraction methodology for NBTI induced degradation using charge pumping based methods

Abstract

In this work, we present a new methodology to determinate and remove the geometric component in charge pumping (CP) based methods, such as on-the-fly interface trap (OTFIT) method. This methodology uses CP-current data of different gate length transistors (L G ) with fixed gate width (W G ) to obtain an empirical model for the remaining carriers in MOSFET channel after switch off. This allows investigating the geometric component (GC) as a function of device gate length during the negative bias temperature instability (NBTI) stress. We present the experimental evidence that GC increases during NBTI stress, which is most likely caused by Coulomb scattering of created traps. This implies that the precision of the estimation of NBTI stress induced-traps is affected as well as their creation dynamic. Consequently, the NBTI power-law time exponent, n is misestimated. We have also presented the experimental results after removing the GC. They show a same n for all transistors. This procedure is a valuable to correct CP-based method data for degraded devices.