EPITAXIAL THIN FILM YBCO MEMBRANE STRUCTURE FOR THERMAL DETECTORS

ABSTRACT

YBa₂Cu₃O₇(YBCO) films have been used at room temperature as conducting oxide electrodes, as well as an excellent template layer for epitaxial growth PZT thin films. This research addresses the fabrication of epitaxial thin film membrane structures based on high temperature superconductor (HTSC) microbolometers for highly sensitive thermal detectors that can be miniaturized for affordable passive millimeter-wave (MMW) imaging. A completely dry etch process is described for fabricating transition-edge microbolometer airbridges based on YBCO film. Pulse Laser Deposition (PLD) grown YBCO film on silicon substrate have anomalies on the surface that must be removed prior to the release process.

keywords:

• YBCO
• YSZ
• MMW
• bolometer
• etch
• release
• process

AKNOWLEDGMENTS

The authors gratefully acknowledge R. Piekarz and D. Washington for developing a reliable lithography process; J. Conrad for ion beam etching; M. Derenge for knowledge and discussions on the application of 3-D optical metrology techniques; J. Pulskamp for the CAD layout and mask design verification; and K. Kirchner for the XRD of the PLD films at the ARL. This project has been partially funded by the DARPA-Microsystems Technology Office.