Ballistic electron emission microscopy studies of Au-CdTe and Au-GaAs interfaces and band structure

Journal Article · · Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena; (United States)

DOI:https://doi.org/10.1116/1.585463· OSTI ID:5263146

Fowell, A E; Williams, R H; Richardson, B E; Cafolla, A A; Westwood, D I; Woolf, D A ^[1]

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1. Univ. of Wales, Cardiff (United Kingdom)

Ballistic electron emission microscopy (BEEM) is an exciting new technique for probing electrical barriers at semiconductor interfaces. It offers huge potential because of its high lateral resolution, which is of the order of 1 nm. The authors have successfully applied the method of Schottky barriers at Au/n-CdTe and Au/n-GaAs interfaces. Simultaneous imaging of the surfaces of the thin gold overlayers an the metal semiconductor interfaces shows no correlation between the surface topography and the interface barrier heights. Measured variations in barrier heights are associated with local defects or contamination at the interfaces. On a nanometer scale, the interface barrier heights for the Au-CdTe show large variations (0.7-1.1 eV). The authors have observed small-scale regions where barrier heights are low. These are probably associated with tellurium precipitates at the interface. By contrast, barrier heights of the Au-GaAs system were exceptionally uniform. These samples were prepared by depositing gold onto atomically clean epitaxially grown GaAs(100) surfaces. Detailed investigations of the voltage dependence of the BEEM current allows the determination of minima in the conduction band of GaAs at the {Gamma}, L, and X points.

• OSTI ID: 5263146
• Journal Information: Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena; (United States), Journal Name: Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena; (United States) Vol. 9:2; ISSN 0734-211X; ISSN JVTBD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
ARSENIC COMPOUNDS
ARSENIDES
CADMIUM COMPOUNDS
CADMIUM TELLURIDES
CHALCOGENIDES
DEPOSITION
ELECTRON EMISSION
ELECTRON MICROSCOPY
ELECTRONIC STRUCTURE
ELEMENTS
EMISSION
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
GOLD
HETEROJUNCTIONS
INTERFACES
JUNCTIONS
MATERIALS
METALS
MICROSCOPY
PNICTIDES
SAMPLE PREPARATION
SEMICONDUCTOR JUNCTIONS
SEMICONDUCTOR MATERIALS
TELLURIDES
TELLURIUM COMPOUNDS
TOPOGRAPHY
TRANSITION ELEMENTS
ULTRAHIGH VACUUM