Advance in Near Field Probe Microwave and mm-wave Microscopy for Surface and Subsurface Characterization of Materials

Near Field Microwave Microscopy is a suitable technique that can be employed for the surface and subsurface characterization of materials. Imaging capabilities span from bulk samples, liquids, additive manufactured materials and devices with the advantage of nondestructive, high spatial resolution and sensitivity features. This technique has been successfully used for many industrial applications, such as composite material inspection, material characterization, and detection of surface cracks in metals. A wide range of applications have been addressed such as dielectric constant measurements, impedance analysis of metals and semiconductor materials/devices, gas and chemical sensing. The capability of microwaves to penetrate into the material allows the electric properties (impedance and dielectric constant) of materials to be quantitatively determined measuring the wave reflected by the material rather than having just topographic information. These distinct characteristics allowed the development of imaging systems that can achieve tasks which are not possible with other imaging techniques such as infrared or optical systems.