  With the development of nanotechnology, the measurement of electrical
properties in local area of materials and devices has become a great need.
Although a lot kind of scanning probe microscope have been developed for
satisfying the requirement of nanotechnology, a microscope technique which can
determine electrical properties in local area of materials and devices is not
yet developed. Recently, microwave microscope has been an interest to many
researchers, due to its potential in the evaluation of electrical properties of
materials and devices. The advance of microwave is that the response of
materials is directly relative to the electromagnetic properties of materials.
However, because of the problem of the structure of probes, nanometer-scale
resolution has not been successful. To achieve the goal, a new structure
microwave probe is required. In this paper, we report a nanostructural
microwave probe. To restrain the attenuation of microwave in the probe, GaAs
was used as the substrate of the probe. To obtain the desired structure, wet
etching was used to fabricate the probe. Different with the dry etching, a
side-etching will occur under the etching mask. Utilizing this property, a
micro tip can be fabricated by etching a wafer, of which a small mask was
introduced on the surface in advance.
