ULTRA-LONG GLASS TIPS FOR ATOMIC-FORCE MICROSCOPY

A new variety of ultra-long tips for atomic force microscopy has been fabricated using photoetchable glass. Photoetchable glass is structure d by UV exposure through a quartz mask followed by a heat treatment an d etch process in hydrofluoric acid. The process is based on different etching rates with a ratio of about 1:20 between unexposed and expose d parts of the glass. Tips longer than 100 mu m with a tip radius down to 20 nm are possible. The cantilevers are made from silicon carbide. The mechanical properties of such long tips are compared, in theory a nd in practice, with conventional cantilevers from silicon and silicon nitride. Their strong sensitivity to friction forces for contrast for mation in atomic force microscopy is discussed.