Fabrication of Al/AlO<sub><italic>x</italic></sub>/Al junctions using pre-exposure technique at 30-keV e-beam voltage

Fabrication of Al/AlO_x/Al junctions using pre-exposure technique at 30-keV e-beam voltage

Lan Dong¹, Xue Guangming^{1, †,}, Liu Qiang¹, Tan Xinsheng¹, Yu Haifeng^{1, 2, ‡,}, Yu Yang^{1, 2}

(a) An e-beam lithographic pattern to fabricate the Josephson junction using the pre-exposure technique. Blue color indicates the area with PMMA dose and orange color the area with MAA dose. (b) An SEM picture of the Josephson junction after shadow evaporation and lift-off. The red square is the junction area with the size of 0.2 μm. (c) Current–voltage characteristic (I–V curve) of a Josephson junction fabricated using this technique. The junction’s critical current is ∼ 100 nA.