Fabrication and measurements using ultra-tall near-field coaxial tips

We present a new method for microfabrication of coaxial silicon tips with heights >50 /spl mu/m. The coaxial silicon tip acts as an electrically small antenna. Microwave measurements using a microfabricated coaxial tip chip are performed with a network analyzer HP8753D and an atomic force microscope (AFM). Scanning near-field microwave microscopy (SNMM) using the ultra-tall coaxial tip is demonstrated with a commercial AFM silicon probe in noncontact mode as a sample.