Fabrication of high-temperature superconducting nanobridges using atomic force microscopy

[摘要] The Josephson effect of high-temperature superconducting nanobridge structures isstudied worldwide. Until now, nanobridges are generally fabricated with focused ionbeam milling on planar thin films. These nanobridges are employed as weak links insuperconducting quantum interference devices (SQUIDs) and used in superconductingflux flow transistors and devices.This project had two main objectives: to improve the sidewall angle of photoresist lines,with the aid of atomic force microscopy (AFM) nanolithography; and to fabricate hightemperatureJosephson junctions by constricting superconductive YBCO lines on MgOsubstrates with AFM nanolithography. The entire fabrication process is explainedincluding photolithography, deposition of the YBCO thin films with pulsed laserdeposition (PLD), nanolithography and wet etching.Although the testing of the junctions did not show any Josephson behaviour, it could bedemonstrated that nanobridge structures can successfully be created by AFMnanolithography.The entire fabrication process has been demonstrated in detail for the benefit of futureresearch.

[发布机构] Stellenbosch University