Alpha-Ta resonators on 300 mm high-resistivity Si wafers reach median internal Q factors exceeding 40 million with substrate loss tangent below 10^{-8}, using industrial processing.
Investigation of tantalum films growth for coplanar resonators with internal quality factors above ten million
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
Alpha-tantalum on silicon is a promising platform for high-coherence superconducting quantum circuits. However, the growth mechanism of alpha-tantalum on silicon remains poorly understood. We present a comprehensive study on alpha-tantalum films growth on various substrate. The decisive role of a substrate material Debye temperature on phase selection mechanism in tantalum films growth is experimentally confirmed, contradicting the prior assumptions on substrate temperature influence. Crucially, we confirm that alpha-tantalum starts growing only after a 7-10 nm thick beta-tantalum underlayer. It results in ranging the critical temperature of {\alpha}-Ta films from 3.77 K to 4.39 K for the total thickness from 20 to 150 nm, respectively. Finally, we compared high-quality Al and Ta coplanar resonators on silicon, demonstrating compact tantalum resonators (4/10.5/4 um) with an internal quality factor exceeding 10 million at single-photon excitation powers.
fields
quant-ph 2years
2026 2verdicts
UNVERDICTED 2representative citing papers
A tunable coupler design enables sub-100 ns two-qubit gates with errors below 10^{-4} between fluxonium qubits over 1 cm distances for modular architectures.
citing papers explorer
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Ultra-high Q-factor superconducting tantalum resonators on 300 mm Si wafers
Alpha-Ta resonators on 300 mm high-resistivity Si wafers reach median internal Q factors exceeding 40 million with substrate loss tangent below 10^{-8}, using industrial processing.
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Long-range tunable coupler for modular fluxonium quantum processors
A tunable coupler design enables sub-100 ns two-qubit gates with errors below 10^{-4} between fluxonium qubits over 1 cm distances for modular architectures.