Junction fabrication by shadow evaporation without a suspended bridge
| Autor: | Thierry Crozes, Wiebke Guichard, Iulian Matei, Thierry Fournier, Cécile Naud, Florent Lecocq, Olivier Buisson, Ioan Pop, Z. H. Peng |
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| Předmět: |
Josephson effect
Fabrication Bioengineering 02 engineering and technology 01 natural sciences law.invention Phase qubit law 0103 physical sciences General Materials Science Electrical and Electronic Engineering 010306 general physics Lithography Physics business.industry Mechanical Engineering General Chemistry 021001 nanoscience & nanotechnology Capacitor Resist Mechanics of Materials Optoelectronics Undercut 0210 nano-technology business Electron-beam lithography |
| Zdroj: | Zhihui Peng |
| Popis: | We present a novel shadow evaporation technique for the realization of junctions and capacitors. The design by e-beam lithography of strongly asymmetric undercuts on a bilayer resist enables in situ fabrication of junctions and capacitors without the use of the well-known suspended bridge (Dolan 1977 Appl. Phys. Lett. 31 337-9). The absence of bridges increases the mechanical robustness of the resist mask as well as the accessible range of the junction size, from 10(-2) µm(2) to more than 10(4) µm(2). We have fabricated Al/AlO(x)/Al Josephson junctions, phase qubit and capacitors using a 100 kV e-beam writer. Although this high voltage enables a precise control of the undercut, implementation using a conventional 20 kV e-beam is also discussed. The phase qubit coherence times, extracted from spectroscopy resonance width, Rabi and Ramsey oscillation decays and energy relaxation measurements, are longer than the ones obtained in our previous samples realized by standard techniques. These results demonstrate the high quality of the junction obtained by this bridge-free technique. |
| Databáze: | OpenAIRE |
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