THz Detection Above 77 K in YBCO Films Patterned by Heavy-Ion Lithography

Research and application of THz technology, pursued all over the last century, are currently focused either on high-performance sources and detectors or on low-cost and rugged devices that are suitable for widespread use. Besides semiconductors, high temperature superconductors are good candidates for next generation superconducting bolometers. We employ the high energy heavy ion (HEHI) lithography for modulating the local structural and electrical properties of high temperature superconducting YBa₂Cu₃O₇ (YBCO) films in a functional way. In this report, measurements of the photoresponse of a prototype device to electromagnetic radiation in the far infrared band (THz region) are presented. It is demonstrated that HEHI lithography is an effective tool to enhance the absorption band of the YBCO film in the infrared spectrum, enabling the THz detection of YBCO sensors, in the superconducting state and above the liquid nitrogen temperature.