Impact of high-κ and SiO₂ interfacial layer thickness on low-frequency (1/f) noise in aggressively scaled metal gate/HfO₂ n-MOSFETs: role of high-κ phonons

Abstract

The effect of high-κ (tHfO2) and interfacial layer thickness (tIL) on the low-frequency (LF) drain current noise is studied in n-MOSFETs with HfO2 gate oxide and TiN metal gate. While a 1/f type spectrum is observed, the dominant noise mechanism is found to be mobility fluctuations. The variation in Hooge's parameter αH is studied and the results are correlated with channel electron mobility (μ). The physical origin of noise fluctuations is then determined from the comparison. The results show that high-κ phonon scattering is likely the dominant source for 1/f noise in aggressively scaled HfO2-metal gate devices. The devices meet the ITRS specification and the selection of tIL becomes significant for use in analog and mixed signal based applications. © 2007 Elsevier B.V. All rights reserved.