Carbon masks for patterning of YBa/sub 2/Cu/sub 3/O/sub x/ submicron Josephson junctions

We have developed a fabrication process for submicron wide YBa/sub 2/Cu/sub 3/O/sub x/ (YBCO) Josephson junctions on bicrystal substrates. The masks patterned in carbon films grown by laser ablation were used for ion beam etching of YBCO films. The carbon deposition parameters providing conservation of critical temperature of YBCO films covered by carbon layers have been found. The test 1.5 to 3 /sub /spl mu//m wide YBCO bridges have been fabricated on single crystal SrTiO/sub 3/ substrates using the developed technology.