title: Production of highly homogeneous Si(100) surfaces by H2O etching: surface morphology and the role of strain.
abstract: The etching of Si(100) surfaces in ultrapure water was studied with a combination of infrared spectroscopy (FTIR) and scanning tunneling microscopy (STM). While the FTIR results show that the initially rough H/Si(100) surface becomes highly homogeneous during etching, a phenomenon generally associated with surface smoothing, STM images reveal that the homogeneity is associated with the formation of well-defined etch hillocks. After many hours of etching, the resulting H-terminated surface is composed of stripes of atomically flat Si(100) terminated by etch hillocks bounded by {111}- and {110}-oriented microfacets. Polarization analysis of the Si-H stretching modes provides strong evidence for uniform dihydride-termination of the flat regions, with the narrow (approximately 25 A) width of these stripes allowing for relaxation of steric strain between neighboring dihydrides. The unusual hill-and-valley etch morphology is attributed to the effects of steric strain on the reactivity of sites on the etched surface.
authors.affiliation: Department of Chemistry, Cornell University, Ithaca, New York 14853-1301, USA.
authors.forename: Marc F
authors.initials: MF
authors.lastname: Faggin
authors.forename: Sara K
authors.initials: SK
authors.lastname: Green
authors.forename: Ian T
authors.initials: IT
authors.lastname: Clark
authors.forename: K T
authors.initials: KT
authors.lastname: Queeney
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Hines