Characterization of Random Telegraph Signal Noise of High-Performance p-MOSFETs With a High- $k$ Dielectric/Metal Gate

The behavior of I_D random telegraph signal (RTS) noise of a p-MOSFET with an advanced gate stack of HfO₂/TaN is experimentally investigated and discussed. The I_D-RTS noise is evaluated on a wafer level (100 sites) for statistical evaluation. The observed ratio of I_D-RTS noise on a wafer is quite similar to that of a p-MOSFET with the conventional plasma-SiON dielectric, which means that the noise distribution on a wafer level is independent of the gate oxide structure and/or material. However, the relative magnitude of change of the drain current to the applied current (ΔI_D/I_D) of the p-MOSFETs with high-k (HK) dielectrics is greater than that of p-MOSFETs with conventional plasma-SiON dielectrics by about six times due to the greater number of preexisting bulk traps in the HK dielectric. Therefore, I_D-RTS noise and its associated 1/f noise can present a serious issue to the CMOSFET with an advanced HK dielectric for low-power analog and mixed-signal applications.