A Modified Charge Pumping Method for Measuring Interface States Up to the Ghz Range

Abstract

In this paper we present a modified on-chip charge pumping method for measuring the interface states in ultra-thin gate oxide complementary metal-oxide-semiconductor (CMOS) technology. The proposed method, which characterizes oxide interface states by applying pulse frequencies up to the GHz range, is used to evaluate the evolution of interface states due to dynamic negative bias temperature instability stress on the p-channel field-effect transistor (pFET). The results show that charge pumping increases linearly at frequencies up to the GHz range and that the time dependence of interface states due to AC negative bias temperature instability (NBTI) stress increases with a power law distribution. In addition, we demonstrate experimentally that the VTH shift due to AC NBTI stress depends on interface states and oxide traps.