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}

Cross-section schematics of pre-exposure technique. (a) The first e-beam lithography, with MAA dose which has no effect on the top PMMA layer, writes the bottom MAA layer. The second one with PMMA dose writes the top layer. (b) After development in the developer (MIBK:IPA = 1:3), the controlled undercuts are formed.