Investigations on Line-Edge Roughness (LER) and Line-Width Roughness (LWR) in Nanoscale CMOS Technology: Part II–Experimental Results and Impacts on Device Variability

In the part I of this paper, the correlation between line-edge roughness (LER) and line-width roughness (LWR) is investigated by theoretical modeling and simulation. In this paper, process-dependence of the correlation between LER and LWR is studied. The experimental results indicate that both Si Fin and nanowire have strongly correlated LER/LWR, and the cross-correlation of two edges depends on the fabrication process. Based on the improved simulation method proposed in the Part I of this paper, the impacts of correlated LER/LWR in the channel of double-gate devices are investigated. The results show that Vth distribution strongly relies on cross-correlation, and can exhibit non-Gaussian distribution and/or multipeak distribution, which enlarges the V
_th
variation.