Intrinsic parameter fluctuations in decananometer MOSFETs introduced by gate line edge roughness

In this paper, we use statistical three-dimensional (3-D) simulations to study the impact of the gate line edge roughness (LER) on the intrinsic parameters fluctuations in deep decananometer (sub 50 nm) gate MOSFETs. The line edge roughness is introduced using a Fourier synthesis technique based on the power spectrum of a Gaussian autocorrelation function. In carefully designed simulation experiments, we investigate the impact of the rms amplitude Delta and the correlation length Lambda on the intrinsic parameter fluctuations in well scaled, but simple devices with fixed geometry as well as the channel length and width dependence of the fluctuations at fixed LER parameters. For the first time, we superimpose in the simulations LER and random discrete dopants and investigate their relative contribution to the intrinsic parameter fluctuations in the investigated devices. For particular MOSFET geometries, we were able to identify the regions where each of these two sources of intrinsic parameter fluctuations dominates.