Abstract
•Covalently bound organic monolayers on Si decrease wear scratches by factor 120.•AFM studies show that for normal loads <8μN almost no wear marks are observed.•The high bond strength of the new SiCC linker is the main cause.•Fluorination of the monolayer and the high monolayer density are also crucial.•These results open up new applications of Si-based NEMS/MEMS.
This study reports on fluorine-containing alkyne-derived monolayers onto Si(111) substrates to obtain densely packed, highly wear-resistant surfaces. The nano-wear properties were measured using atomic force microscopy (AFM). The presence of the fluorinated monolayers was found to enhance the wear properties of the silicon surfaces, with a decrease of the depth of wear scratches of up to 120 times as compared to the unmodified surface. Ultimately, the scratch depth was only 6nm for a heptadecafluoro-alkyl based monolayer for scratching normal forces as high as 38μN.