Impact of strain and source/drain engineering on the low frequency noise behaviour in n-channel tri-gate FinFETs

Flicker noise in n-channel nanoscale tri-gate fin-shaped field-effect transistors

“…[5][6][7][8][9][10] Extensive investigations of the Lorentzian components with temperature were reported recently, identifying the traps originating from process steps used for realization of the source and drain contacts and traps related to the process steps used for the channel optimization. 6,9 Regarding the 1/f noise, it has been ascribed to carrier number fluctuations (CNF) due to carrier exchange between the gate dielectric traps near the interface and the channel, [5][6][7][8] whereas the charge fluctuations in the gate dielectric can induce additional fluctuations of the carrier mobility, giving rise to the so-called correlated mobility fluctuations (CMF). 11 Recently, we have proposed an analytical generic CMF compact noise model for single-gate n-channel and p-channel nanoscale bulk metal-oxide-semiconductor fieldeffect transistors (MOSFETs), describing the 1/f noise accurately and continuously in all operation regions.…”

On the 1/f noise of triple-gate field-effect transistors with high-k gate dielectric

“…As will be shown, 1 / f ␥ noise is observed, with a ␥ Ͻ 1 for low frequencies and approaching or equal to 1 at higher frequencies, confirming previous observations. 8,9 At the same time, it is demonstrated that this can be interpreted in terms of a profile in the oxide trap density ͑N ot ͒, which decays with further distance from the Si-SiO 2 interface. This stands in contrast with trap profiles on planar transistors, revealed by different techniques.…”

“…More recently, it has been shown that nMuGFETs with an SiO 2 / HfO 2 high-k stack exhibit an unusual 1 / f noise behavior, 8,9 which is illustrated by Fig. 1 for such transistors: when representing the product ͓f ϫ S I ͑f͔͒ versus the frequency f, one obtains a curve which increases with f and subsequently saturates in the high-frequency region.…”

“…This type of spectra has also been found in p-channel devices 10 and is independent of the device geometry or temperature. 8 While it was clearly shown that the 1 / f noise is governed by number fluctuations, no straightforward explanation for the phenomenon could be given, although a relationship with the selective epitaxial growth ͑SEG͒ of the source/drain areas has been observed. 8 Therefore, it is the aim here to compare the LF noise of trigate finFETs on SOI substrates, processed with different high-k gate dielectrics ͑HfO 2 versus HfSiON͒.…”

“…8 While it was clearly shown that the 1 / f noise is governed by number fluctuations, no straightforward explanation for the phenomenon could be given, although a relationship with the selective epitaxial growth ͑SEG͒ of the source/drain areas has been observed. 8 Therefore, it is the aim here to compare the LF noise of trigate finFETs on SOI substrates, processed with different high-k gate dielectrics ͑HfO 2 versus HfSiON͒. As will be shown, 1 / f ␥ noise is observed, with a ␥ Ͻ 1 for low frequencies and approaching or equal to 1 at higher frequencies, confirming previous observations.…”