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 d-RTS ) in high-κ gate dielectric and metal-gate MOSFETs. The samples were stressed at typical BTI oxide electric field (~7 MV/cm) and I d-RTS amplitude (ΔI d-RTS ) distributions were measured before and after P/NBTI stress. It is shown that I d-RTS degradation (ΔI d-RTS =I d-RTS ) in NBTI devices exhibits a wider amplitude distribution than the PBTI one. In addition, we trace trapped charge-induced saturation current I D,sat degradation in P/NBTI stress. As a result, the statistical analysis indicates that ΔI D,sat =I D,sat of the p-MOSFET is larger than ΔI D,sat =I D,sat 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. © 2013 The Japan Society of Applied Physics.