Fabrication of the Tip of GaAs Microwave Probe by Wet Etching

In order to develop a new structure microwave probe, the fabrication of micro tip on the GaAs wafer surface was studied. The effects of the shape, direction, and size of etching mask to the fabricated tip were discussed in details. By finding the most suitable etching conditions, a tip having 7 μm high, 1.4 aspect ratio, and 50 nm curvature radius was formed. The experimental result indicates that the tip having the similar capability to sense the surface topography of materials as that of commercial atom force microscope (AFM) probe.