Low-frequency noise in nFinFETs of different dimensions processed in strained and non-strained SOI wafers

Abstract

The results of low-frequency noise investigation in fully-depleted (FD) nFinFETs of Weff = 0.02 to 9.87 µm, Leff = 0.06 to 9.9 µm, processed on standard (SOI) and strained (sSOI) wafers are presented. It is shown that the McWhorter noise is typical at zero back gate voltage for the devices studied and the density of the corresponding noisy traps in the SiO₂ portion of the gate oxide is, as a rule, much higher than that in the HfO2 portion. The results on the McWhorter noise are used for studying the behavior of the electron mobility µ and the free electron density NS in the channel at V* ≥ 0.4 V where V* is the gate overdrive voltage. It is also shown that the Linear Kink Effect (LKE) Lorentzians appear in the low-frequency noise spectra at an accumulation back gate voltage and that the parameters of those Lorentzians are different for the sSOI and SOI nFinFETs. This is the first observation of the LKE noise under a back-gate accumulation bias for sufficiently wide nMuGFET.