AVS 47th International Symposium
    Semiconductors Tuesday Sessions
       Session SC+EL+OF-TuA

Paper SC+EL+OF-TuA9
Attaching Aromatic Molecules to the Si(001) Surface via Oxygen and Sulfur Tethers

Tuesday, October 3, 2000, 4:40 pm, Room 306

Session: Organic Chemistry on Semiconductor Surfaces
Presenter: S.K. Coulter, University of Wisconsin, Madison
Authors: S.K. Coulter, University of Wisconsin, Madison
M.P. Schwartz, University of Wisconsin, Madison
J. Liu, University of Wisconsin, Madison
R.J. Hamers, University of Wisconsin, Madison
Correspondent: Click to Email
Phenol, benzenethiol and phenyl disulfide have been used as model systems to compare the bonding of chemically-similar aromatic molecules to the Si(001)-2x1 surface through different Group VI tethers. The behavior of these substituted aromatic hydrocarbons on the Si(001) surface has been investigated using Fourier transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS) and Scanning Tunneling Microscopy (STM). Both FTIR and XPS indicate that phenyl disulfide bonds exclusively through the sulfur substituent groups. Phenol and benzenethiol molecules bond predominately through their oxygen/sulfur substituent groups, although a small minority may chemisorb on the surface via ring attachment. Thermal studies indicate that the molecules attached to the surface via sulfur or oxygen tethers are stable to temperatures above 550 K. STM studies show that these molecules attach directly to the silicon dimer and, in the case of phenyl disulfide, form ordered rows of aromatic rings.