Stress evolution during growth and atomic-scale surface structure effects in transition-metal thin films

Thin films are defined by an extremely high ratio of the in-plane dimensions to the thickness, resulting in very high surface-to-volume ratios. For this reason, the surface characteristics of a film play an important role in the properties of the film as a whole. This research focused on the connections between the properties and the surface state of metallic thin films. High resolution in-situ stress measurements were made during the ultra-high vacuum evaporative deposition of polycrystalline Cu films and homoepitaxial (111)-oriented Cu and Ag films. The measurements were enabled through the development of two high resolution in-situ stress monitoring devices that minimized sample placement and vibrational error through compact and monolithic ultra-high vacuum compatible designs. These devices allowed in-situ stress measurements with unprecedented sensitivities while the device electronics enabled the study of systems in real-time with high data acquisition rates. Measurements were made during growth and interruptions of growth as the films formed and thickened. In the earliest stages of a growth cycle, when only a small fraction of a monolayer is deposited, the elastic component of the adatom-surface interaction dominates the stress evolution. The early stage observations are analyzed through a first- order expansion of the thermodynamic surface stress which allows for direct extraction and measurement of the force-dipole associated with the adatom-surface interaction.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Materials Science and Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Friesen, Cody A. (Cody Alden), 1978-

Advisor dc:contributor.advisor

• Carl. V. Thompson.

• Materials Science and Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/28351

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/28351