Towards Enabling Two Metal Level Semi-Damascene Interconnects for Superconducting Digital Logic: Fabrication, Characterization and Electrical Measurements of Superconducting NbxTi(1-x)N

Abstract

NbxTi(1-x)N is a promising alternative to replace conventional Nb in superconducting devices. In this work, short loop devices with metal lines and vias were fabricated in IMEC 300-mm pilot line using direct metal etch, semi-damascene approach. Single line resistance of NbxTi(1-x)N wires show that >95% of devices meet the expected resistance of <5000 Ω/μm and leakage measurements show that >95% of devices have low leakage of <1E–16 A/ μm. Low temperature measurements show that the NbxTi(1-x)N wires have transition temperature of 12.5K within 0.5K that of thin film and a critical current of 0.15 mA, within 2X of theoretical maximum.