Fabrication and Characterization of an Attonewton-sensitivity Si Cantilever with an Nb Micro-ring
Fabrication and Characterization of an Attonewton-sensitivity Si Cantilever with an Nb Micro-ring
- 주제(키워드) Si cantilever , MEMS , Attonewton , Nb superconductor , Micro-ring , Mechanical detection
- 발행기관 한국물리학회
- 발행년도 2012
- 총서유형 Journal
- UCI G704-000411.2012.60.7.018
- KCI ID ART001652652
- 본문언어 영어
초록/요약
We have fabricated ultrasensitive silicon cantilevers integrated with a superconducting Nb micro-ring as a key part of a flux quantum-based force measurement system, and have characterized both their mechanical and superconducting properties by mechanical methods. A 50 nm-thick Nb ring with the inner and outer radii of 5 µm and 10 µm was mounted by DC magnetron sputtering and lift-off on the end of a 410 µm-long, 4 µm-wide and 340 nm-thick single-crystalline silicon cantilever. The cantilever showed force sensitivity as good as 4.2 aN/√Hz at 3 K, which was estimated from its spring constant of 2.6 ×10<sup>-5</sup> N/m and a quality factor of 31000. The superconducting property of the Nb micro-ring was observed from the variation of the cantilever vibration amplitude while the vibration was driven by an excitation coil, showing a transition temperature of 7 K. The superconducting transition was also confirmed through an electrical transport measurement for a separately prepared Nb strip film on a silicon wafer.
more