发表机构
University of Chicago; Argonne National Laboratory; Fairfield University; Delft University of Technology（芝加哥大学; 阿贡国家实验室; 费尔菲尔德大学; 代尔夫特理工大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究针对温度受限的超导探测器制备，通过ICPCVD在150℃下沉积SiN$_x$薄膜，发现降低N$_2$/SiH$_4$前驱体比例及施加RF衬底偏压可降低其4-7 GHz下的微波损耗，为相关应用提供了实用工艺参数。
AI 中文摘要
低损耗介质膜是超导电路的重要组成部分，应用范围涵盖量子信息到天体物理用超导探测器。在毫米波探测器电路中，介质损耗可能是效率和谐振器性能的限制因素。一些有利的探测器制备架构要求在远低于常规实现低介质损耗的温度下进行介质沉积。本研究针对温度受限的超导探测器制备，表征了通过感应耦合等离子体化学气相沉积（ICPCVD）在150℃下沉积的氮化硅（SiN$_x$）薄膜。我们使用超导铌微带谐振器，在约4-7 GHz下测量这些薄膜的介质损耗角正切，并通过将温度相关的谐振频率拟合到两能级系统模型来提取损耗。我们在不同介质沉积之间改变N$_2$/SiH$_4$前驱体流量比，发现损耗随N$_2$/SiH$_4$比例降低而明显减小的趋势。我们还发现，与无偏压沉积的薄膜相比，沉积过程中施加射频衬底偏压会降低损耗。这些结果确定了前驱体比例和衬底偏压是改善超导探测器电路用低温SiN$_x$的实用工艺参数。
英文摘要
Low-loss dielectric films are an important component of superconducting circuits with applications ranging from quantum information to superconducting detectors for astrophysics. In millimeter-wave detector circuits, dielectric loss can be the limiting factor on efficiency and resonator performance. Some advantageous detector fabrication architectures require dielectric deposition at temperatures substantially lower than those conventionally used to achieve low dielectric loss. In this work, we characterize silicon nitride (SiN$_x$) films deposited by inductively coupled plasma chemical vapor deposition (ICPCVD) at $150\,^{\circ}\mathrm{C}$ for use in temperature-constrained superconducting detector fabrication. We measure the dielectric loss tangent of these films at $\sim 4-7$ GHz using superconducting niobium microstrip resonators and extract the loss by fitting the temperature-dependent resonant frequency to a two-level-system model. We vary the N$_2$/SiH$_4$ precursor-flow ratio between dielectric depositions and find a clear trend of decreasing loss with decreasing N$_2$/SiH$_4$. We additionally find that applying an RF substrate bias during deposition reduces the loss compared to films deposited without bias. These results identify precursor ratio and substrate bias as practical process parameters for improving low-temperature SiN$_x$ for superconducting detector circuits.
Comments6 pages, 4 figures, Conference Manuscript for the ASC 2026 Special Issue of the IEEE Transactions on Applied Superconductivity
