Random doping and oxide roughness induced fluctuations in nanoscale semiconductor devices

Random doping and oxide roughness induced fluctuations in nanoscale semiconductor devices are analyzed by using self-consistent Poisson-Schr\"{o}dinger computations. A very fast and robust technique based on linearization of the transport equations is presented for the computation of fluctuations of various parameters (such as threshold voltages, terminal currents, and cutoff frequencies) of the semiconductor device. This technique is computationally much more efficient than the traditional Monte-Carlo approach and yields information on the sensitivity of device parameters fluctuations to the locations of doping and oxide thickness fluctuations. Hence, it can be used in the design of fluctuation resistant structures of semiconductor devices. Sample simulation results obtained by using the linearization technique are reported for MOSFET devices with channel lengths under 25 nm and compared with results obtained by using the Monte-Carlo technique.