Auger electron spectroscopy, transmission electron microscopy, and scanning electron microscopy studies of Nb/Al/Nb Josephson junction structures

Journal Article · Mon Jun 01 04:00:00 EDT 1987 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.338334· OSTI ID:6652303

Chang, C C; Gurvitch, M; Hwang, D M; Blonder, C W

Al films deposited on Nb can be oxidized and used to make Josephson junction devices. We studied the structure of Al films deposited under ''warm'' (estimated to be near 200 /sup 0/C) and ''cold'' (near room temperature) conditions because the cold films produced better Josephson junction devices. For the warm case, the Al film was composed of islands with open channels between them, which we attribute to a high mobility of the Al atoms that lowers the island nucleation density. The Nb surface was extremely flat, which we ascribe to the high surface atom mobility at the higher deposition temperature. The cold Al film was of uniform thickness which can be explained by a high island nucleation density. The cold Nb films had an undulating surface, caused by the lack of surface atom mobility during deposition. There was no evidence of Al-Nb interdiffusion, even after postdeposition heating to 300 /sup 0/C. Auger spectroscopy, transmission electron microscopy, and scanning electron microscopy were needed to obtain these definitive conclusions.

• Research Organization: Bell Communications Research, Inc., Red Bank, New Jersey 07701-7020
• OSTI ID: 6652303
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 61:11; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101 -- Metals & Alloys-- Preparation & Fabrication
360102 -- Metals & Alloys-- Structure & Phase Studies
420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALUMINIUM
ATOM TRANSPORT
CHALCOGENIDES
CHEMICAL REACTIONS
CRYSTAL STRUCTURE
DIFFUSION
ELEMENTS
FABRICATION
FILMS
INTERFACES
JOSEPHSON JUNCTIONS
JUNCTIONS
METALS
MICROSTRUCTURE
MORPHOLOGY
NEUTRAL-PARTICLE TRANSPORT
NIOBIUM
NIOBIUM COMPOUNDS
NIOBIUM OXIDES
NUCLEATION
OXIDATION
OXIDES
OXYGEN COMPOUNDS
RADIATION TRANSPORT
REFRACTORY METAL COMPOUNDS
SUPERCONDUCTING JUNCTIONS
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS