Impact of the Interfacial Layer on the Low-Frequency Noise (1/f) Behavior of MOSFETs

Abstract—The impact of the interfacial layer thickness on the low-frequency (LF) noise (1/f noise) behavior of n- and p-channel MOSFETs with high-κ gate dielectrics and metal gates is in-vestigated. Decreasing the interfacial layer thickness from 0.8 to 0.4 nm affects the 1/f noise in two ways. 1) The mobility fluctu-ations mechanism becomes the main source of 1/f noise not only on pMOS devices, as usually observed, but also on nMOS devices. 2) A significant increase of the Hooge’s parameter is observed for both types of MOSFETs. These experimental findings indicate that bringing the high-κ layer closer to the Si−SiO2 interface enhances the 1/f noise mainly due to mobility fluctuations. Index Terms—High-κ gate dielectrics, Hooge’s parameter, interfacial layer, low-frequency (LF) noise, metal gates, mobility fluctuations. I