Mechanism for nearly ohmic behavior in annealed Au//ital n/-GaAs Schottky diodes

Journal Article · Sat Jul 15 04:00:00 EDT 1989 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.343543· OSTI ID:6092056

Leon, R P; Newman, N; Liliental-Weber, Z; Weber, E R; Washburn, J; Spicer, W E

The origin of the ohmic behavior observed after annealing Au//ital n/-GaAs /l brace/110/r brace/ Schottky diodes was investigated by electron-beam-induced current (EBIC) measurements of diode plan views and cross sections, combined with standard scanning electron microscopy and transmission electron microscopy techniques. The large leakage currents responsible for this behavior arise at the periphery of the deposited gold films, where elongated gold crystallites which lie on the GaAs surface are observed after heat treatment. These crystallites are typically 2--5 ..mu..m long, 500--2000 A wide, and are crystallographically oriented along the GaAs (110) direction. EBIC imaging demonstrated that a space-charge region was present under the peripheral area showing the gold crystallites. Comparison of current collection as measured with EBIC between annealed and unannealed diodes shows a large reduction in current collection under and around the periphery of the annealed diodes. These data allow attribution of the ohmic behavior to a recombination current. Experiments done with overlapping Au evaporations show that recombination on the bare GaAs surface between the observed crystallites surrounding each annealed diode is the main component of this recombination current, and thus of the large leakage current.

• Research Organization: Department of Materials Science and Mineral Engineering, University of California, and Center for Advanced Materials, Lawrence Berkeley Laboratory, Berkeley, California 94720(US); Stanford Electronics Laboratories, Stanford University, Stanford, California 94305
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6092056
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 66:2; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ANNEALING
ARSENIC COMPOUNDS
ARSENIDES
BEAMS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON BEAMS
ELECTRON MICROSCOPY
ELEMENTS
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
GOLD
HEAT TREATMENTS
LEPTON BEAMS
MATERIALS
METALS
MICROSCOPY
N-TYPE CONDUCTORS
OHM LAW
PARTICLE BEAMS
PHYSICAL PROPERTIES
PNICTIDES
RECOMBINATION
SCANNING ELECTRON MICROSCOPY
SCHOTTKY BARRIER DIODES
SEMICONDUCTOR DEVICES
SEMICONDUCTOR DIODES
SEMICONDUCTOR MATERIALS
SPACE CHARGE
TRANSITION ELEMENTS
TRANSMISSION ELECTRON MICROSCOPY