Universal Feature of Trap-Density Increase in Aged MOSFET and Its Compact Modeling

Abstract

Our investigation focuses on accurate circuit aging prediction for bulk MOSFETs. A self-consistent aging modeling is proposed, which considers the trap-density N trap increase as the aging origin. This N trap s considered in the Poisson equation together with other charges induced within MOSFET. It is demonstrated that a universal relationship of the N trap increase as a function of integrated substrate current, caused by device stress, can describe the MOSFET aging in a simple way for any device-operating conditions. An exponential increase with constant and unitary slope of the N trap is found to successfully predict the aging phenomena, reaching a saturation for high stress degradation. The model universality is verified additionally for any device size. Comparison with existing conventional aging modeling for circuit simulation is discussed for demonstrating the simplifications due to the developed modeling approach.