Microwave microscopy technique for micro/nanoscale characterization of dielectric, semiconductor and magnetic materials

The Scanning Microwave Microscopy (SMM) is a novel tool providing the ability to perform broad band high frequency microwave measurements and imaging at the microscopic and nanoscopic length scales. Measuring electromagnetic response of materials on microscopic length scales will accelerate the production and development of next generation emergent technologies. Exploiting the potentialities of the microwave microscopy technique in characterizing different kinds of materials and the detailed study of its properties are presented in this thesis work. Dynamic chemical etching technique has been introduced to demonstrate the possibility to shape the pin of a commercial coaxial connector to get an ultra-sharp tip. This method of etching yielded fine tapering of tips with tip apex sizes less than 1 μm. The near-field characteristic of these fabricated probes shows the focusing ability of these probes that are in the order of few microns. In the analysis of the dielectric properties of materials, it has been introduced a new definition of characteristic frequency to get the dielectric constant of planar dielectric materials by measuring the frequency point of the 2 phase shift of a microwave signal passing through the material. The use of frequency and time domain methods for multilayers characterization has been described. The phenomena based on the characteristic frequency also have been used to de-embedding the SMM measurements for higher oxide thickness MOS systems where the parallel plate approximation is not valid. The analysis of the frequency dependence of such measurements has shown better sensitivity at higher frequencies. Surface characterization of magnetic materials using SMM provided insight into the local variation of magnetic properties on the surface of the magnetic films. Hysteretic ii behaviour of the reflection coefficient S11 with the external bias field was observed. Local study of ferromagnetic resonance has shown promising results in terms of SMM spectroscopy.