Interfacial layer quality effects on low-frequency noise (1/ f) in p-MOSFETs with advanced gate stacks

Abstract

The effects of interfacial layer quality on the low-frequency noise behavior of p-channel MOSFETs with high-κ gate dielectric and metal gate are investigated. Devices with chemically grown SiO 2 interfacial layers (0.8 nm) are compared with N 2O (0.8 nm) interfacial oxides. A 0.4 nm SiO 2 interfacial layer device is used for comparison purposes. A cross-over kind of behavior has been observed in N 2O devices, which occur at lower gate voltages (∼1.2–1.3 V) when normalized spectral densities and input referred noise are investigated. This behavior is found to be closely related to the observed transconductance variation in these devices. The dominant mechanism of 1/ f noise is found to be Hooge’s mobility fluctuations. Hooge’s parameter, as a figure of merit, shows an increase for 0.4 nm devices when compared to 0.8 nm devices, while 0.8 nm N 2O devices confirm their cross-over nature.