Title :
Deposition of noble metal contacts on YBa/sub 2/Cu/sub 3/O/sub 7-x/ thin films
Author :
Hahn, R. ; Schaffter, T. ; Klockau, J. ; Fotheringham, G.
Author_Institution :
Tech. Univ. Berlin, Germany
fDate :
3/1/1993 12:00:00 AM
Abstract :
Ohmic contacts with low specific contact resistivities between YBa/sub 2/Cu/sub 3/O/sub 7-x/ thin films and noble metals have been fabricated using ion beam sputter etching and RF-plasma contact preparation. The influence of deposition parameters has been investigated. Specific contact resistivities in the 10/sup -8/ Omega -cm/sup 2/ range at 77 K have been achieved and were evaluated using cross bridge Kelvin test structures with sizes varying between 5 and 50 mu m. The failure rate of wires bonded onto high-temperature superconductor (HTSC)-Au/Ag pads was unacceptable in most cases. Substantial improvements have been achieved with Cr/Ti adhesion sublayers. Deposition parameters for optimum pull test results on MgO and LaAlO/sub 3/ substrates are presented.<>
Keywords :
barium compounds; electron beam deposition; high-temperature superconductors; metallisation; ohmic contacts; sputter deposition; sputter etching; superconducting thin films; yttrium compounds; 5 to 50 micron; 77 K; Au-Ag metallisation; Cr-Ti sublayers; Cr/Ti adhesion sublayers; HTSC; LaAlO/sub 3/ substrates; MgO substrates; RF-plasma contact preparation; YBa/sub 2/Cu/sub 3/O/sub 7-x/ thin films; cross bridge Kelvin test structures; deposition parameters; failure rate; ion beam sputter etching; low specific contact resistivities; noble metal contacts; ohmic contacts; optimum pull test; Bonding; Bridges; Conductivity; Ion beams; Kelvin; Ohmic contacts; Sputter etching; Sputtering; Testing; Wires;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
