Local Probe Oxidation of Self-Assembled Monolayers on Hydrogen-Terminated Silicon
-
Yang, Menglong; Wouters, Daan; Giesbers, Marcel; Schubert, Ulrich S.; Zuilhof, Han
- Abstract:
- Local probe oxidation experiments by conductive AFM have been performed on a hexadecyl
monolayer and a N-hydroxysuccinimide (NHS)-ester-functionalized undecyl (NHS-UA) monolayer assembled on
hydrogen-terminated (i.e., unoxidized) silicon. The oxidation conditions for the mild oxidation of the top terminal
groups of monolayers and the deep oxidation of the underlying silicon into silicon oxide were investigated. The
results show that the bias threshold for the AFM tip-induced oxidation of the top groups of monolayers on oxidefree
silicon can be reduced by 2 V for the methyl-terminated hexadecyl monolayer and even by 3.5 V for the active
NHS-ester-terminated undecyl monolayer, in comparison to a methyl-terminated octadecyl trichlorosilane (OTS)
monolayer on oxidized silicon. Upon such local mild oxidation, the active NHS ester group of the NHS-UA monolayer
is selectively cleaved off to generate carboxyl-containing monolayer nanopatterns, opening further possibilities
for subsequent patterned multifunctionalization.
- Year:
- 2009
- Type of Publication:
- Article
- Journal:
- ACS Nano
- Volume:
- 3
- Number:
- 10
- Pages:
- 2887 - 2900