The interplay of self-heating effects and static RTF in nanowire transistors

Random Telegraph Noise Fluctuations (RTF) manifest themselves as fluctuations in transistor threshold voltage and drive (on) current. RTF is caused by random trapping and detrapping of charges lying at the inversion channel of the device under consideration close to the oxide-semiconductor interface [1]. Traditionally RTF were important only in analog design at low frequencies [2]. However, as CMOS is scaling into sub-100 nm regime, the effect of RTF as well as its variability is not negligible any more even in digital design [3]. In fact, we have illustrated in past work that the presence of a single negatively charged trap at the source end of the channel in a nanowire transistor can have very degrading effect on the on-current [4]. In these simulations we have utilized 3D Monte Carlo device simulator in which the short-range portion of the Coulomb interaction was accounted for by our real-space molecular dynamics model, details of which can be found in Ref. [5]. The model properly accounts for both the short-range and the long-range component of the Coulomb interaction and has been well recognized in the literature and applied in many other studies [6].