Publication Date

2014

Document Type

Honors Thesis

Department

Chemistry

Keywords

Silicides-Oxidation, Surface chemistry, Infrared spectroscopy, Oxidation, Nanotechnology, Hydrosilylation, Si(100), Oxidation of surfaces, Organic functionalizaties

Abstract

Simultaneous control of nanoscale topography and chemical functionalization of the Si(100) rough surface could provide great potential for creating a library of surfaces for microorganism growth studies. However, nanopatterning both topography and chemistry concurrently has yet to be accomplished. The Si(100) surface can be patterned on the nanoscale by deoxygenated water acting as an anisotropic etchant, resulting in a hydrogen-terminated surface of hillocks 50-100 nm in diameter with {110} microfacets. Oxidation and hydrosilylation have both been shown to proceed relatively easily on this surface. Although the mechanism of this oxidation reaction is not entirely understood, both mono- and dihydrides will evolve from Si-H species, through an O3Si-H intermediate, into Si-O species. With oxidation time and flow rate controlled, the {110} monohydride species preferentially oxidize before any other hydrogen species on the rough surface. Hydrosilylation occurs via a thermally induced radical reaction, in which a silyl radical is created by breaking a silicon-hydrogen bond, and a hydrocarbon chain is covalently attached on that site. If hydrosilylation occurs preferentially at H-terminated sites, a multifunctionalized surface could be created by oxidation followed by hydrosilylation. The identity of the chemical species are confirmed using FTIR and wettability studies are conducted using Contact Angle Goniometry.

Language

English

Comments

61 pages : illustrations (some color). Honors Project, Smith College, 2014. Includes bibliographical references (pages 59-61)

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