Evaluation of BEOL scaling boosters for sub-2nm using enhanced-RO analysis

In this work, the impact of metal hybrid height (H^2) and airgap (AG) scaling boosters are evaluated based on an enhanced Ring Oscillator (RO) framework that accounts for Place and Route (PnR) aspects of the back end of line (BEOL) interconnects. When targeting best performance, extended AG with high aspect ratio (AR) lines appears to be the optimal choice as it allows reducing both capacitance (C) and resistance (R). Combining AG with H^2 provides minimum C at an increased R making it more suitable for power optimization.