Chemistry and resistance at metal contacts to YBa sub 2 Cu sub 3 O sub 7 high T sub c superconducting thin films

Conference · Thu Jan 25 04:00:00 EST 1990 · AIP Conference Proceedings (American Institute of Physics); (USA)

OSTI ID:6549912

Schmidt, M T; Ma, Q Y; Weinman, L S; Wu, X; Yang, E S ^[1]; Chang, Chin-An ^[2]

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1. Microelectronics Sciences Laboratories, Columbia University, New York, NY (USA)
2. IBM Watson Research Center, Yorktown Heights, NY (USA)

X-ray photoelectron spectroscopy (XPS) and electrical characterization have been used to investigate metal contacts to thin films of superconducting YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} (YBCO). The metals studied are Au, Pt, Pd, Sn, and Ti, which cover a wide range of physical properties including reactivity with oxygen and bulk resistivity. XPS was also used to investigate the sputter cleaning and subsequent heating of the YBCO films prior to contact formation. Contacts for electrical study were defined by a shadow mask, while contacts studied by XPS were formed by sequential deposition of several A of metal. XPS of the O 1s, Cu 2p, and the various metal core levels confirm that the more reactive metals cause more disruption at the metal/YBCO interface. These observations of interface chemistry are correlated with contact resistivity measured at room temperature and at 77 K. We find that although Au, Pt and Pd have similar contact resistivity at room temperature, only the Au contacts show a large decrease in contact resistance at 77 K. Ti and Sn have much higher contact resistivities at room temperature than the noble metals. These results are discussed in terms of interface chemistry and material properties.

• OSTI ID: 6549912
• Report Number(s): CONF-891092--
• Conference Information: Journal Name: AIP Conference Proceedings (American Institute of Physics); (USA) Journal Volume: 199:1
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CLEANING
COPPER COMPOUNDS
COPPER OXIDES
ELECTRIC CONDUCTIVITY
ELECTRIC CONTACTS
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
ELECTRON SPECTROSCOPY
EQUIPMENT
FABRICATION
FILMS
HEAT TREATMENTS
HIGH-TC SUPERCONDUCTORS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PHYSICAL PROPERTIES
SPECTROSCOPY
SPUTTERING
SUPERCONDUCTING FILMS
SUPERCONDUCTORS
SURFACE CLEANING
SURFACE FINISHING
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES