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Precise slit-width control of niobium apertures for superconducting LEDs
Jae-Hoon Huh1, Claus Hermannstädter, Hiroyasu Sato
1Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan. hjaehoon@es.hokudai.ac.jp
Nanotechnology
|December 21, 2010
Summary
We developed a new three-step method for precise nanometer-scale niobium etching. This technique enables the fabrication of advanced superconducting devices, like Josephson junctions, with improved performance.
Area of Science:
- Materials Science
- Nanotechnology
- Condensed Matter Physics
Background:
- Precise fabrication of nanometer-scale structures is crucial for advanced superconducting devices.
- Niobium (Nb) etching presents challenges due to its material properties and the need for high resolution.
Purpose of the Study:
- To introduce a novel three-step procedure for precise nanometer-scale niobium etching.
- To demonstrate the application of this technique in fabricating superconducting devices, specifically superconductor-semiconductor-superconductor (S-Sm-S) Josephson junctions.
Main Methods:
- Utilized a three-step procedure involving high contrast resist patterning and sacrifice layer formation under high radio frequency (RF) power.
- Employed reactive ion etching (RIE) with CF(4) gas and a positive tone resist for Nb etching.
- Controlled etching rates (ER) of the resist, Nb, and underlying layer for precise slit-width control.
Main Results:
- Achieved precise slit fabrication of 80 and 200 nm thick Nb apertures.
- Fabricated S-Sm-S Josephson junctions with lengths as small as 80 nm.
- Demonstrated critical currents as high as 50 µA in the fabricated Josephson junctions.
Conclusions:
- The novel three-step etching procedure enables precise nanometer-scale Nb fabrication.
- The technique is suitable for producing high-performance superconducting devices like short Josephson junctions.
- Potential applications extend to superconducting light-emitting diodes (SC LEDs).
