Impact of distributed Bragg reflectors on the intrinsic detection efficiency of superconducting nanowire single-photon detectors

In this study, we investigate the impact of substrates with distributed Bragg reflectors (DBRs) on the proximity effect during the fabrication of superconducting nanowire single-photon detectors (SNSPDs) using electron beam lithography. We compare the linewidth compression and line edge roughness of nanowires prepared on three different DBRs substrates. Additionally, we characterize the variations in switching current (I s w ) and intrinsic detection efficiency (IDE) at a 2.2-K temperature. The results show that when the substrates are composed of low atomic number materials, such as Si and SiO 2 , the proximity effect is significantly mitigated. As a consequence, the lithography quality of nanowires is effectively improved, thus enhancing the IDE of SNSPDs. This study is expected to provide new insights into the fabrication of SNSPDs and lay the foundation for the preparation of high-performance and high-uniformity large-area devices.