Patterned thick photoresist layers for protection of protruding structures during wet and dry etching processes

Thick photoresist (about 40 m) was patterned and used as a protective layer for protruding structures (sharp, high aspect ratio atomic force microscope tips) in wet (buffered hydrofluoric acid) and dry (reactive ion etching) etching. The process and results of its use are discussed, and some applications are proposed.