Selected Publications
Feng Zhang, Adam M. Larsen, Daniel A. Findley, Robert C. Davis, and Matthew R. Linford (et al.)
Covalently bonded monolayers of two monofunctional aminosilanes (3-aminopropyldimethylethoxysilane. APDMES, and 3-aminopropyldiisopropylethoxysilane, APDIPES) and one trifunctional aminosilane (3-aminopropyltriethoxysilane, APTES) have been deposited on dehydrated silicon subsumes by chemical vapor deposition (CVD) at 150 C and low pressure (a few Torr) using reproducible equipment Standard surface analytical techniques such as x-ray photoelectron spectroscopy (XPS). contact angle gontometry, spectroscopic ellipsometry. atomic force microscopy, and time-of-flight secondary ion mass spectroscopy (ToF-SIMS) have been employed to characterize the resulting Films These methods indicate that essentially constant surface coverages arc obtained over a wide range of gas phase concentrations of the aminosilanes XPS data further indicate that the NIs/Si2p ratio is Iliac! after CVD with the trifunctional Wane (APTES) compared to the monofunctional ones, with a higher NIs/Si2p ratio lot APDMES compared to that for APDIPES A FM images show an average surface roughness of 0 12 - 0 15 inn among all three aminosilane films Stability tests indicate that APDIPES films retain most of their integrity at pH 10 for several hours and are more stable than APTEs or APDMES layers The films also showed good stability against storage in the laboratory ToF-SIMS of these samples showed expected peaks, such as CN-, as well as CNO-, which may arise from an interaction between monolayer amine groups and silanols. Optical absorption measurements on adsorbed cyanine dye at the surface of the aminosilane films show the formation of dimer aggregates on the surface This is further supported by ellipsometry measurements. The concentration of dye on each surface appeals lobe consistent with the density of the amines
Jonathan Abbott, Barry M. Lunt, Matthew C. Asplund, Guilin Jiang, Matthew R. Linford, Richard R. Vanfleet, and Robert C. Davis (et al.)
A highly durable optical disk has been developed for data archiving. This optical disk uses tellurium as the write layer and carbon as a dielectric and oxidation prevention layer. The sandwich style CTeC film was deposited on polycarbonate and silicon substrates by plasma sputtering. These films were then characterized with AFM, SEM, TEM, EELS, and ellipsometry and were tested for writability and longevity. Results show the films were uniform in physical structure, stable, and able to form permanent pits. Data was written to a disk and successfully read back in a commercial DVD drive.
Matthew R. Linford, Robert C. Davis, David Jensen, Rebecca Olsen, and Richard Vanfleet (et al.)
Nitesh Madaan, Aaron Terry, Robert C. Davis, and Matthew R. Linford (et al.)
Instrumentation and Techniques Symposia
Guilin Jiang, Felipe Rivera, Supriya S. Kanyal, Robert C. Davis, Richard Vanfleet, Barry M. Lunt, and Natthew R. Linford
The plastic substrates, reflective layers, dyes, and adhesives of four archival-grade DVDs and one standard-grade recordable DVD were analyzed to determine their chemical compositions and/or physical dimensions. Chemical analyses by ATR-FTIR, ToF-SIMS, XPS and EDX/STEM show that all these DVDs use very similar polycarbonate plastic substrates and acrylate-based adhesives, but different reflective layers and dye write layers. In addition, physical measurements by AFM show differences in the DVD groove depth, width, and other dimensions. These chemical and physical analyses may help explain variations in DVD lifetimes and facilitate development of the next generation of archival-grade DVDs.
Todd D. Wickard, Emily Nelsen, Nitesh Madaan, Robert C. Davis, and Matthew R. Linford (et al.)
We report the first attachment of polymers with pendant vinyl groups to hydrogen-terminated silicon(111) (Si(111)-H); 1,2-polybutadiene (M(w) = 3200-3500 g/mol) was attached to Si(111)-H under mild conditions at room temperature with visible light. We also report the partial functionalization, in solution, of 1,2-polybutadiene with various thiols using thiol-ene chemistry and the Subsequent attachments of these compounds to Si(111)-H. The partially functionalized or unfunctionalized polybutadienes allow further functionalization at the surface through their unreacted carbon-carbon double bonds. We present this as a useful strategy for Silicon Surface modification, Surfaces were characterized with contact angle goniometry, spectroscopic ellipsometry X-ray photoelectron spectroscopy (XIS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and atomic force microscopy (AFM).