Photoemission spectroscopy study of thin Cr overlayers on NH[sub 3]/GaAs(100)

Journal Article · Wed Mar 01 04:00:00 EST 1995 · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States)

DOI:https://doi.org/10.1116/1.579399· OSTI ID:6495793

Park, K T; Cao, J; Gao, Y ^[1]; Ruckman, M W ^[2]

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1. Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States)
2. Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)

The interface formation of Cr/NH[sub 3]/GaAs(100) and its temperature dependence using synchrotron radiation photoemission and resonance photoemission spectroscopies have been investigated. We observed that at [ital T]=90 K the initial deposition of Cr stimulated nitridation of the GaAs substrate and subsequent interface reaction was characterized by Cr-induced substrate disruption. Annealing of the thus formed interface to room temperature and above caused further Cr--GaAs reaction. The metallicity of the Cr overlayer was examined using constant initial-state spectroscopy (CIS) of Cr 3[ital d] with [ital E][sub [ital i]]=1.7 eV below the Fermi level. The CIS spectra showed a maximum at the photon energy [ital h][nu]=50.0 eV followed by a second broad maximum centered at [ital h][nu]=56--58 eV depending on the stage of the interface formation. As the nominal Cr coverage increases from 1 to 10 A, the valence band photoemission spectra show a shift of the Cr 3[ital d] band toward the Fermi level. At the same time, the second maximum in CIS gradually dominates over the first, suggesting the evolution of the Cr overlayer to a more metallic state. The sensitivity of the second maximum in its peak position and intensity to the density of states near the Fermi level indicates that this maximum likely results from many body electron interactions. The results show that CIS can provide valuable information about the transition of a thin overlayer to a metallic state.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 6495793
• Journal Information: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States), Journal Name: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States) Vol. 13:2; ISSN 0734-2101; ISSN JVTAD6
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
AMMONIA
ANNEALING
ARSENIC COMPOUNDS
ARSENIDES
CHROMIUM
ELECTRONIC STRUCTURE
ELEMENTS
EMISSION
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
HEAT TREATMENTS
HYDRIDES
HYDROGEN COMPOUNDS
INTERFACES
LAYERS
METALS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
PHOTOEMISSION
PNICTIDES
SECONDARY EMISSION
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0065-0273 K
TRANSITION ELEMENTS