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In this article, the impact of several electrical and technological parameters on a particular type of Lorentzian noise, occurring in deep submicron silicon-on-insulator (SOI) metal–oxide–semiconductor field-effect transistors with an ultrathin gate dielectric is described and a semi-empirical model is proposed that captures the main features of the experimental behavior. It is shown that the noise takes place in both n- and p-channel partially depleted SOI transistors. The excess Lorentzians are also found in the n-channel fully depleted devices studied, whereby the noise plateau amplitude [SI(0)] increases for a more negative back-gate bias, putting the back interface into stronger accumulation. The dependence of the characteristic time constant τ and SI(0) on transistor length, drain, front- and back-gate bias is reported, where from a first-order model is derived. The latter is based on the idea that the excess Lorentzian noise originates from filtered shot noise induced by majority carriers, that are injected in the floating body of the transistors by electron valence-band tunneling across the ultrathin (2.5 nm) gate oxide.

It is shown that in thin-gate partially depleted silicon-on-insulator metal-oxide-semiconductor field-effect transistors (PD SOI MOSFETs) unexpected front-back-gate coupling effects occur when the back gate is operated in accumulation. This is particularly true for front-gate biases (VGF) beyond the threshold for electron valence-band tunneling to occur, inducing the so-called linear kink effect (LKE). As a consequence of this coupling, both the drain current and the drain-current noise spectral density are reduced in the LKE regime. Moreover, for a back-gate bias into stronger accumulation, the LKE regime is shifted to higher VGF in absolute value. Another consequence of the front-back-gate coupling is the appearance of the back-gate-induced (BGI) Lorentzian component in the noise spectra measured for an accumulated back gate in a wide range of VGF. Similar effects have also been detected in thin-gate fully depleted SOI MOSFETs. It is demonstrated that all these front-back coupling effects can be explained by considering the increased body-source leakage currents and, hence, the body-source conductance induced by the accumulation back-gate voltage where the BGI Lorentzian is attributed to the Nyquist noise in the back-gate-induced body-source conductance affected by the capacitive character of the body-source impedance.

This work describes the low-frequency noise of forward biased shallow p-n junctions fabricated in epitaxial silicon substrates. Particular emphasis is on the effect of silicidation on the low-frequency noise spectral density . It will be demonstrated that the observed 1 noise is significantly larger in Co-silicided junctions compared with the nonsilicided ones. A detailed analysis of the current and geometry dependence of leads to the conclusion that the 1 noise is of the generation-recombination (GR) type, with the responsible GR centres homogeneously distributed over the device area. From the correlation with the forward current-voltage (I-V) characteristics, it is derived that GR fluctuations in the hole current through the + region cause the increased 1 noise in the silicided devices.

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