Investigation of Positive and Negative Bias Temperature Instability of High-κ Dielectric Metal Gate Metal–Oxide–Semiconductor-Field-Effect-Transistors by Random Telegraph Signal

Abstract

We investigate the impact of positive and negative bias temperature instability (P/NBTI) on the current degradation by using the drain current random telegraph signal (I dRTS) in high-κ gate dielectric and metal-gate MOSFETs. The samples were stressed at typical BTI oxide electric field (∼7 MV/cm) and I dRTS amplitude (ΔI dRTS) distributions were measured before and after P/NBTI stress. It is shown that I dRTS degradation (ΔI dRTS/I dRTS) in NBTI devices exhibits a wider amplitude distribution than the PBTI one. In addition, we trace trapped charge-induced saturation current I Dsat degradation in P/NBTI stress. As a result, the statistical analysis indicates that ΔI Dsat/I Dsat of the p-MOSFET is larger than ΔI Dsat/I Dsat of the n-MOSFET. Moreover, the lifetime of the device is numerically estimated based on current degradation with or without RTS. We consequently found that P/NBTI lifetime comes worse by considering the effect of RTS.

Impact of Voltage-Accelerated Stress on Hole Trapping at Operating Condition

“…Our study should be distinguished from past studies (e.g. [3], [6], [7], [16]) which examined the voltage dependence of a trap's capture characteristics. In these studies, the change in capture behavior stems from the effect of the applied gate voltage (Vg) on the capture barrier energy and local inversion charge density.…”