用于超导平面微波电路的悬空桥制备工艺研究

Fabrication of air-bridges for superconducting thin-film microwave circuits

在超导微波电路芯片中,通常存在影响信号传输和控制的杂散信号,利用超导悬空桥连接电路不同接地平面,可有效抑制微波线路中的寄生杂散模式。利用光刻胶作为支撑层,采用直流磁控溅射、反应离子刻蚀(RIE)、深紫外曝光光刻等微加工方法,制备了连接复杂微波电路不同接地平面的悬空桥结构,并给出了制备工艺流程及悬空桥结构的低温超导特性表征。试验结果表明,该悬空桥制备工艺可用于目前比较复杂的超导平面微波电路制备。

In the superconducting microwave circuit chips, the spurious signals that affect the transmission and control of signals are usually present, and proper grounding between different ground planes of using superconducting air - bridges can ef- fectively suppress the parasitic spurious modes in the microwave circuits . Using the photoresist as a supporting layer and many micromachining methods such as direct current（DC） sputter, reactive ion etching （RIE） and lithography fabricated air- bridge structure connecting different ground planes of complex microwave circuits. In addition, the fabrication process and the character- ization on the low temperature superconductivity of air - bridges were also described. The experimental results show that the fabri- cation process of superconducting air - bridge can be used for the fabrication of relatively complex superconducting thin - film mi- crowave circuits.