| AVS 63rd International Symposium & Exhibition | |
| Thin Film | Friday Sessions |
| Session TF-FrM |
| Session: | CVD, ALD and Film Characterization |
| Presenter: | Brian Johnson, Brigham Young University |
| Authors: | B.I. Johnson, Brigham Young University M.R. Linford, Brigham Young University |
| Correspondent: | Click to Email |
Silanes are arguably the most important reagents for chemically modifying surfaces. They have the unique ability to attach to silanol (SiOH) groups while imparting desired functionality. Indeed, they are extensively used to modify silica for chromatography and silicon wafers to create attachment layers for biosensors and bioarrays. Of course, HMDS is an important silane that is widely used in the semiconductor industry. Interestingly, most of the reports in the literature on silane deposition describe their liquid phase deposition. The obvious drawbacks of this approach are its lack of reproducibility and the consumption of large amounts of solvent both in the deposition and rinsing of the surfaces. Clearly there are health/safety issues associated with this use of solvent. Its advantages are simplicity – only beakers/simple glassware are required. The gas phase deposition of silanes has exactly the opposite advantages. It offers greater reproducibility and control, but the equipment required is much more complex and expensive. Nevertheless, the semiconductor and related industries much prefer the latter chemical vapor deposition (CVD) direction. Here we describe the CVD of various silanes under the controlled conditions offered by a commercial deposition system. We describe the effect of reactive functionality in the silane on deposition. We show how varying the temperature substantially changes film growth (silane deposition). We describe system cleanliness issues and the means by which carry over between runs can be nearly eliminated. We discuss the deposition of both monofunctional and trifunctional silanes. Films are characterized by X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, and contact angle goniometry. Water contact angles and film thicknesses of hydrophobic silanes are strongly correlated. Best conditions for the gas phase deposition of some important silanes are presented.