Analytical Modeling of RDF Effects on the Threshold Voltage in Short-Channel Double-Gate MOSFETs

M. Graef, F. Hain, F. Hosenfeld, F. Horst, A. Farokhnejad (Tech. Hochschule Mittelhessen, Germany), B. Iniguez (Univ. Rovira i Virgili, Spain), A. Kloes (Tech. Hochschule Mittelhessen, Germany)

The massive scaling of semiconducting devices is still the most favorable way to enhance device performance to this day. This leads to emerging ultra low power devices with channel lengths down to 14 nm. In this small dimensions the discretization of doping profiles gains influence on the device current, namely random dopant fluctuations (RDF). Therefore, the topic of variability in terms of fabricating these devices is getting more and more important. The simulation analysis in this paper should give a deeper insight on the variability problems emerging in this new dimension regimes regarding doping discretization and fabrication tolerances. An improved model is introduced which allows an estimation of the RDF-based threshold voltage deviation sVth for MOSFET devices. The simulations are done using randomized profiles with the FEM-Simulator TCAD Sentaurus.