Towards single‐trap spectroscopy: Generation‐recombination noise in UTBOX SOI nMOSFETs

Abstract

AbstractAn 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)