Temperature impact on the Lorentzian noise induced by electron valence-band tunneling in partially depleted SOI p-MOSFETs

Abstract

In partially depleted (PD) silicon-on-insulator (SOI) MOSFETs with thin gate oxides, a particular effect named linear kink effect (LKE) occurs, which is due to the fact that the body potential is strongly affected by majority carriers injected in the body by the electron valence-band (EVB) tunneling through the ultra-thin gate oxide. This unexpected phenomenon induces a second peak in the transconductance gm curve and an excess Lorentzian noise in the low-frequency noise spectrum. A model based on RC filtered shot noise due to the EVB tunneling current and the forward current of the source-body junction was recently proposed at room temperature. In this work, the focus is on the temperature impact on the Lorentzian noise induced by valence-band electron tunneling in partially depleted SOI p-MOSFETs. For the first time, a Lorentzian noise filtered by the same RC network as the shot noise of the EVB tunneling current has been observed in the LKE operation at low temperature. It seems that the EVB tunneling current can also accompany an excess Lorentzian noise due to traps localized at the Si/gate oxide interface. A simple extension of the model developed by Lukyanchikova et al. is proposed and validated by experimental results from room temperature down to 80 K.