Technologies

Atomically sharp micro-fabricated tips are used in atomic force microscopy (AFM) for scanning near-field microwave microscopy (SNMM) to create an image of the tiny topography on or under a surface. These tips can be created via semiconductor processing, attaching carbon nanotubes to AFM tips or focused ion beam milling.

However, these techniques are expensive, and can’t be used to create tips with a height greater than 30 micrometers. With a short tip, capacitive coupling with the cantilever it is mounted on limits the ability to create an image. A taller tip would decrease parasitic capacitance and increase sensitivity. UW-Madison researchers have developed a method for fabricating a microscopic coaxial tip with a height greater than 30 micrometers. A coaxial tip and a coplanar waveguide are formed on a silicon substrate. The first layer of the tip shaft is made of a conductive material. Over the first layer, a layer of non-conducting material is deposited, followed by a layer of a different conducting material. An oxide etch exposes the first conductive layer at the tip.

The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing a method for fabricating a microscopic coaxial tip with a height greater than 30 micrometers for use in atomic force microscopy.