An experimentally validated analytical model for gate line-edge roughness (LER) effects on technology scaling

This letter introduces an analytical model to represent line-edge roughness (LER) effects on both off-state leakage and drive current for sub-100-nm devices. The model partitions a given device into small unit cells along its width, each unit cell assumes a constant gate length (i.e., cell's width is small compared to LER spatial frequency). Gn analytical model is used to represent saturated threshold voltage dependency on the unit cell's gate length. Using this technique, an efficient and accurate model for LER effects (through Vt, variations) on off-state leakage and drive current is proposed and experimentally validated using 193 and 248 lithography for devices with 80-nm nominal gate lengths. Assuming that the deviation from the ideal 0-LER case remains constant from generation to generation, the model predicts that 3 nm or less LER is required for 50-60-nm state-of-the-art devices in the 0.1-mum technology node. Based on data presented, we suggest that the LER requirement for this technology node is attainable with an alternated phase-shift type of patterning process.