Abstract
Covalently attached organic monolayers on etched silicon nitride (SixN4; x 3) surfaces were prepared by reaction of SixN4-coated wafers with neat or solutions of 1-alkenes and 1-alkynes in refluxing mesitylene. The surface modification was monitored by measurement of the static water contact angle, XPS, IRRAS, AFM, and ToF-SIMS, and evidence for the formation of Si-C bonds is presented. The etching can be achieved by dilute HF solutions and yields both Si-H and N-H moieties. The resulting etched SixN4 surfaces are functionalized by terminal carboxylic acid groups in either of two ways: (a) via attachment of a 10-undecenoic acid 2,2,2-trifluoroethyl ester (trifluoro ethanol ester) and subsequent thermal acid hydrolysis; (b) through attachment of a photocleavable ester, and subsequent photochemical cleavage, as this would allow photopatterned functionalized SixN4. The carboxylic acids are successfully used for the attachment of oligopeptides (aspartame) and complete proteins using EDC/NHS chemistry. Finally, an amino-terminated organic monolayer can be formed by reaction of HF-treated SixN4 surfaces with a N-(-undecylenyl)phthalimide, which yields an amino-terminated surface upon deprotection with hydrazine.
Original language | English |
---|---|
Pages (from-to) | 6233-6244 |
Journal | Langmuir |
Volume | 23 |
DOIs | |
Publication status | Published - 2007 |
Keywords
- hydrogen-terminated silicon
- self-assembled monolayers
- ion mass-spectrometry
- laser interference lithography
- tof-sims spectra
- alkyl monolayers
- multivariate-analysis
- organic monolayers
- porous silicon
- scribed silicon