TY - JOUR AU - Sarang Mittal AU - Kazemi Adachi AU - Nicholas Frattini AU - Maxwell Urmey AU - Sheng-Xiang Lin AU - Alec Emser AU - Cyril Metzger AU - Luca Talamo AU - Sarah Dickson AU - David Carlson AU - Scott Papp AU - Cindy Regal AU - Konrad Lehnert AB -

The dielectric loss of silicon nitride (Si3⁢N4) limits the performance of microwave-frequency devices that rely on this material for sensing, signal processing, and quantum communication. Using superconducting resonant circuits, we measure the cryogenic loss tangent of either as-deposited or high-temperature annealed stoichiometric Si3⁢N4 as a function of drive strength and temperature. The internal loss behavior of the electrical resonators is largely consistent with the standard tunneling model of two-level systems (TLSs), including damping caused by resonant energy exchange with TLSs and by the relaxation of nonresonant TLSs. We further supplement the TLS model with a self-heating effect to explain an increase in the loss observed in as-deposited films at large drive powers. Critically, we demonstrate that annealing remedies this anomalous power-induced loss, reduces the relaxation-type damping by more than 2 orders of magnitude, and reduces the resonant-type damping by a factor of 3. Employing infrared absorption spectroscopy, we find that annealing reduces the concentration of hydrogen in Si3⁢N4, suggesting that hydrogen impurities cause substantial dissipation.

BT - Phys. Rev. Applied DA - 2024-05 DO - 10.1103/PhysRevApplied.21.054044 IS - 5 N2 -

The dielectric loss of silicon nitride (Si3⁢N4) limits the performance of microwave-frequency devices that rely on this material for sensing, signal processing, and quantum communication. Using superconducting resonant circuits, we measure the cryogenic loss tangent of either as-deposited or high-temperature annealed stoichiometric Si3⁢N4 as a function of drive strength and temperature. The internal loss behavior of the electrical resonators is largely consistent with the standard tunneling model of two-level systems (TLSs), including damping caused by resonant energy exchange with TLSs and by the relaxation of nonresonant TLSs. We further supplement the TLS model with a self-heating effect to explain an increase in the loss observed in as-deposited films at large drive powers. Critically, we demonstrate that annealing remedies this anomalous power-induced loss, reduces the relaxation-type damping by more than 2 orders of magnitude, and reduces the resonant-type damping by a factor of 3. Employing infrared absorption spectroscopy, we find that annealing reduces the concentration of hydrogen in Si3⁢N4, suggesting that hydrogen impurities cause substantial dissipation.

PY - 2024 EP - 054044 T2 - Phys. Rev. Applied TI - Annealing reduces Si3⁢N4 microwave-frequency dielectric loss in superconducting resonators UR - https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.21.054044 VL - 21 ER -