SUBSTRATE FOR MANUFACTURING JOSEPHSON ELEMENT

PURPOSE:To manufacture of Nb pattern, the accuracy of size thereof is high and which has reproducibility, even when using a fluoric acid group etching liquid by employing a GaP of GaAs substrate. CONSTITUTION:The GaP substrate 7 is coated with an Nb film as a base electrode 3 through electron-beam evaporation, a photo-resist is applied, and a desirable pattern is exposed. The whole is treated by a developer, washed by water and dried, and etched by the etching liquid having the composition of fluoric acid:nitric acid:water=1:2:7, washed by water and spin-dried, and ultrasonic- washed in acetone, and the Nb base electrode pattern 3 is obtained. A junction hole 5 by SiO by a stencil mask using a photo-resist and an upper electrode 6 emploting Pb-Bi are prepared through a lift-off method, and the Nb group Josephson junction element is manufactured.