论文标题
通过定向反应性蒸发生长的超导锡膜
Superconducting TiN films grown by directional reactive evaporation
论文作者
论文摘要
我们报告了一种新型的方法，即通过反应性电子束沉积增长了强大的氮化钛（TIN）薄膜。可以通过控制1.1*10^-6至3.1*10^-5 MBAR}的沉积压力和从10nm到300nm的膜厚度D来调整正常状态板电阻和超导临界温度（TC）。对于10nm厚的薄膜，板电阻达到1361Ω/\正方形，T_C = 0.77K，它转化为板电感的估计值，如L_ \ Square = 2.4NH/\ Square。从反应性蒸发的方向性中受益，我们使用抗掩码和升降过程制造了带有微米大小尺寸的RF测试设备，这对于溅射或原子层沉积方法是不可能的。光谱测量结果导致两个不同设备几何形状的板电感值一致，质量因子范围为Q = 300-2200。损失可能是由于膜的形态组成中存在氧硝酸钛。提升过程的灵活性表明，反应蒸发的锡在于量子电路周围的支撑结构（例如读取谐振器或紧凑的片上过滤器）的应用。
We report a novel method of growing strongly-disordered superconducting titanium nitride (TiN) thin films by reactive electron-beam deposition. The normal state sheet resistance and superconducting critical temperature (Tc) can be tuned by controlling the deposition pressure in the range of 1.1*10^-6 to 3.1*10^-5 mbar} and film thickness d from 10nm to 300nm. For 10nm thick films, the sheet resistance reaches 1361 Ω/\square and T_c = 0.77K, which translates into an estimate for the sheet inductance as large as L_\square = 2.4nH/\square. Benefiting from the directionality of reactive evaporation, we fabricated RF test devices with micron-sized dimensions using a resist mask and a lift-off process, which would be impossible with sputtering or atomic layer deposition methods. The spectroscopic measurements result in consistent sheet inductance values in two different device geometries and the quality factors ranged from Q = 300-2200. The loss is likely due to the presence of titanium oxynitride in the morphological composition of our films. The flexibility of the lift-off process suggest applications of reactively-evaporated TiN for making supporting structures around quantum circuits, such as readout resonators or compact on-chip filters.
