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In this work, both time domain random telegraph noise (RTN) and frequency domain Lorentzian spectra due to generation-recombination (GR) centres are studied in ultra-thin buried oxide (UTBOX) silicon-on-insulator (SOI) nMOSFETs. As will be shown, for a Si film-related RTN, the corner frequency is moderately dependent on the gate voltage, while a strong VGS dependence is found for an oxide RTN. This translates in the time domain in a different behaviour of the capture and the emission time constants and their ratio: for an oxide RTN, an exponential gate voltage dependence is observed for the time constant ratio, from which the trap depth in the oxide can be derived. On the other hand, for a defect in the silicon film, the ratio remains constant around one, indicating that the Fermi level is close to the trap level in that case. Based on this analysis, one can distinguish RTN due to gate oxide traps from RTN due to silicon film defects. [ABSTRACT FROM AUTHOR]

An overview is given on the possibilities of using generation-recombination (GR) noise as a tool for defect spectroscopy in semiconductor materials and devices. The method is illustrated by n-channel MOSFETs fabricated on silicon-on-insulator (SOI) substrates with an ultra-thin buried oxide (UTBOX). As will be shown, the use of fully depleted (FD) UTBOX devices offers some unique opportunities and challenges. In the first instance, one can apply the standard GR noise spectroscopy in function of the temperature to derive the relevant deep-level parameters like the activation energy, the capture cross section and the concentration. In addition, some new type of spectroscopy can be applied to defects in the silicon film by exploiting the front- and/or back-gate bias dependence of the Lorentzian noise parameters. Finally, it is shown that for small geometry transistors the GR noise is generated by one or only a few centres. This becomes obvious in the time domain, where the channel current exhibits random telegraph signal (RTS) fluctuations. The up and down time constants and the relative RTS amplitude can be used to derive the GR centre parameters and, moreover, its spatial location, when combined with numerical device simulations. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]