7nm BEOL Integration and Qualification for Manufacturing

7nm BEOL process has been successfully applied for high volume manufacturing with the benefit of EUV technology. The patterning fidelity of EUV lithography was improved ~70%, which leads to better reliability. The variation of R (resistance) and C (capacitance) was reduced from previous generation by better LER (line edge roughness) and CD (critical dimension) uniformity. A "Cu reflow" process was adopted to improve fill capability in smallest design features in BEOL contacts and metal islands enabling aggressive chip scaling. HPC application was also introduced providing lower resistance for intermediate and thick metal layers and including a new enhanced MIM capacitor.