We have found the deposition technology at which the interface roughne
ss of Nb/Si multilayer is strongly correlated and decreases with depos
ited layer number. On the basis of our Nb/Si multilayer we succeeded t
o prepare ten-fold stacked Josephson junction (JJ). Basic electric pro
perties of stacked JJ are presented. (C) 1998 Elsevier Science Ltd. Al
l rights reserved.