Strain-induced surface reactivity: Low temperature Cr/W(110) nitridation

Journal Article · Wed May 01 04:00:00 EDT 1991 · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (USA)

DOI:https://doi.org/10.1116/1.577661· OSTI ID:5589677

Shinn, N D; Tsang, K ^[1]

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1. Surface Science Division 1114, Sandia National Laboratories, Albuquerque, New Mexico 87185 (US)

Synchrotron photoelectron and Auger electron spectroscopies have been used to study the reaction of nitrogen with ultrathin chromium overlayers vapor deposited on W(110). Molecular nitrogen dissociates via a metastable {pi}-bonded intermediate on Cr(110), the strained (1{times}1) Cr/W(110) monolayer and the (2{times}2) Cr/W(110) bilayer surfaces. However, the activation energy for dissociation of the {pi}-bonded intermediate is lower on the strained overlayers than on Cr(110). This has been exploited to grow ultrathin CrN layers on W(110), which are spectroscopically indistinguishable from chromium nitride formed by reacting atomic Cr and N{sub 2} simultaneously on W(110) at 300 K. This demonstrates that nitridation proceeds via energetically equivalent pathways at isolated Cr adatoms on W(110) and at majority sites on the strained Cr/W(110) overlayers. In addition, an anomalous narrow band of states near the Fermi level is found for these surface nitrides and, tentatively, is attributed to unique surface or interface states of CrN:W(110). These findings suggest that strained pseudomorphic overlayers may be useful templates for low temperature nitride film growth.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5589677
• Journal Information: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (USA), Journal Name: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (USA) Vol. 9:3; ISSN JVTAD; ISSN 0734-2101
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CHEMICAL REACTIONS
CHROMIUM
CHROMIUM COMPOUNDS
CHROMIUM NITRIDES
COATINGS
ELEMENTS
ENERGY LEVELS
FERMI LEVEL
METALS
NITRIDATION
NITRIDES
NITROGEN COMPOUNDS
PNICTIDES
STRAINS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
TUNGSTEN
VAPOR DEPOSITED COATINGS