Изготовление Сверхпроводниковых Туннельных Структур С Использованием Электронно-Лучевой Литографии

Abstract

The technology for manufacturing submicron Nb - AlN - NbN tunnel junctions using electron beam lithography has been developed and optimized. Investigations have been carried out to select the exposure dose, development time, and plasma-chemical etching parameters to obtain the high quality of junctions (the ratio of the resistances below and above the gap Rj/Rn). The use of a negative resist ma-N 2400 with lower sensitivity and better contrast in comparison with a negative resist UVN 2300-0.5 has improved the reproducibility of the structure fabrication process. The submicron (area from 2.0 to 0.2 µm2) tunnel junctions Nb - AlN - NbN with high current density and quality parameter Rj / Rn> 15 were fabricated. The spread of parameters of submicron tunnel structures across the substrate and the reproducibility of the cycle-to-cycle process of fabrication of tunnel structures has been experimentally measured.