Preparation method of superconducting array structure

Abstract

The invention discloses a preparation method of a superconducting array structure. The preparation method comprises the following steps: coating a positive photoresist on a bridge used for preparing a superconducting array structure on a substrate material, and forming a sample with a positive photoresist masking layer through exposure and development; the bridge for preparing the superconducting array structure comprises a silicon substrate, a SiO2 layer, an Au layer and an Nb layer, wherein the Au layer and the Nb layer are located on the SiO2 layer and located in a superconducting array structure preparation area. The Au layer and the Nb layer are arranged on the SiO2 layer from bottom to top; evaporating an Al layer on the sample; removing the positive photoresist masking layer and the Al layer growing on the positive photoresist masking layer through a solvent stripping process, and cleaning the sample; performing reactive ion etching on the cleaned sample, and removing the Nb layer in the same area as the projection position of the positive photoresist masking layer; and removing the Al layer in an area different from the projection position of the positive photoresist masking layer, and cleaning to obtain the superconducting array structure formed by the Au layer and the residual Nb layer.

Description

Technical field [0001] The present invention relates to the field of thin film microstructure, and more particularly to a preparation method of a superconducting array structure. Background technique [0002] The superconducting array structure is a periodic superconducting island array structure prepared on a metal film. figure 1 The scanning electron micrograph of the superconducting array structure prepared in the embodiment of the present invention is shown. Metal film becomes a superconductor due to superconducting proximity effect. Due to the pattern shape of the structure (such as triangular array, square array, honeycomb array, etc.), cycle size (island spacing), the size (diameter) of the island can be easily changed through microcompression techniques, which can affect samples The magnetic flux state in the magnetic field state provides a valuable research object for the study of superconducting mechanism and magnetic flux. In the material selection, high-quality sample...

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Problems solved by technology

[0005] 1. Since the Nb islands are deposited after electron beam exposure, the Au-Nb interface at the deposition site may be affected by residual glue, thereby affecting the quality of the sample

[0006] 2. Since Nb is easily oxidized during deposition, which affects its superconducting critical temperature, in order to ensure a higher superconducting critical temperature, it is required that the chamber of the instrument can reach a higher vacuum degree or deposit Nb at a faster rate during deposition.

But for making an island array, such as Figure 7 As shown, due to the irregularity of the exposed area (area other than the circle), electron beam lithography is used, and electrons are scattered in the adjacent substrate to cause optical proximity effect (optical proximity effect), which affects the graphic integrity of the unexposed area. resulting in irregular shape of the final sample

Figure 8 For the samples we fabricated with this protocol, it was demonstrated that electron beam lithography resulted in structural deformations in the case of irregularly shaped exposed areas.

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