Reducing quantum-regime dielectric loss of silicon nitride for superconducting quantum circuits

作者：Hanhee Paik, Kevin D. Osborn · 发表于：Applied Physics Letters · 年份：2010 · DOI：10.1063/1.3309703 · 被引用次数：95 · 研究领域：Diamond and Carbon-based Materials Research、Semiconductor materials and devices、Thin-Film Transistor Technologies

The loss of amorphous hydrogenated silicon nitride (a-SiNx:H) is measured at 30 mK and 5 GHz using a superconducting LC resonator down to energies where a single-photon is stored, and analyzed with an independent two-level system defect model. Each a-SiNx:H film was deposited with different concentrations of hydrogen impurities. We find that quantum-regime dielectric loss tangent tan δ0 in a-SiNx:H is strongly correlated with N–H impurities, including NH2. By slightly reducing x we are able to reduce tan δ0 by approximately a factor of 50, where the best films show tan δ0≃3×10−5.