Cornell Researchers Lower Tantalum Qubit Deposition Temperature to 200°C Using Krypton Gas Sputtering
Mohamed Abdel-Kareem2026-08-19T08:37:12-07:00A research team led by Cornell University Assistant Professor Valla Fatemi has developed a low-temperature fabrication process for tantalum-based superconducting qubits, resolving a major manufacturing bottleneck for superconducting quantum processing units (QPUs). Detailed in Nature Materials ("Krypton-sputtered tantalum films for scalable high-performance quantum devices"), the team substituted standard argon gas with krypton gas during magnetron sputtering, lowering the required substrate deposition temperature for body-centered cubic (α-phase) tantalum on silicon from >400∘C to 200∘C. [ Cornell Low-Temperature Tantalum Sputtering Architecture ] │ ┌────────────────────────────────────────┼────────────────────────────────────────┐ ▼ ▼ ▼ Krypton Sputtering Physics BEOL Semiconductor Compatibility Transmon Performance Metrics • Heavy Kr Ion Momentum Transfer. • [...]