LKE And BGI Lorentzian Noise In Strained And Non-Strained Tri-Gate SOI Finfets With Hfsion/Sio_2 Gate Dielectric

摘要

The LKE (Linear Kink Effect) and BGI (Back-Gate-Induced) Lorentzians present in the drain current noise spectra of fully-depleted tri-gate n- andpFinFETs, fabricated on sSOI and SOI substrates with HfSiON/SiO_2 gate dielectric are described.It is shown that the analysis of the parameters of LKE and BGI Lorentzians allows to find the values of (C_(eq)/m'β ~2), β and [jevb/(m'β)~2] where C_(eq) is the body-source capacitance, m' ≈ 1, β is the body factor and Jevb is the density of the EVB current flowing through the gate dielectric.As a result, the following effects were observed for the first time: (i) (C_(eq)/m'β ~2) decreases with increasing gate overdrive voltage |V| and depends sub-linearly on the effective fin width We!! under strong inversion conditions; (ii) in depletion and weak inversion where (Ceqjp2) is independent of |V*| the proportionality (C_(eq)/β ~2) ∝ W_(eff) is observed for an effective width W_(eff) > 0.87 u,m while (C_(eq)/β ~2) becomes independent on W_(eff)for W_(eff)< 0.87 u.m; (iii) the value of p for the FinFETs investigated is higher than for their planar counterparts; (iv) in spite of the fact that strain affects the barrier height at the Si/SiO2 interface, the EVB current densities j_(EVB) for sSOI and SOI devices are equal; (v) the values of j_(EVB) for the HfSiON/SiO_2-devices are much higher than for the HfO_2/SiO_2-ones studied previously. It is also shown that the gate overdrive voltage |V*| at which the LKE Lorentzians start to appear is as low as 0.25 V.