The target of this thesis is to fabricate through Silicon via (TSV) structures based on Si-bench technology for high-speed transmission interface. In this process, Si via with a depth of 250 £gm were formed by dry etching on a 500 £gm thick <111> Si wafer. The TSV were then obtained by removing the bottom of the silicon wafer using grinding technique. To reduce microwave loss of high frequency signal transmission, we oxidized the TSV by oxygen wet oxidation at a temperature of 1000 oC. Finally, conductive paths through the TSV were formed by filling silver epoxy into the via and dry at a temperature of 200 oC for 1 hour. The s parameters of the high speed TSV structure was characterized by a Vector Network Analyzer. Si-bench technology can effectively improve system integration and performance while reducing cost and size of the module package. . Key words: Through silicon via, microwave loss, s parameters

abstract: Losses in commercial microwave dielectrics arise from spin excitations in paramagnetic transition metal dopants, at least at reduced temperatures. The magnitude of the loss tangent can be altered by orders of magnitude through the application of an external magnetic field. The goal of this thesis is to produce “smart” dielectrics that can be switched “on” or “off” at small magnetic fields while investigating the influence of transition metal dopants on the dielectric, magnetic, and structural properties. A proof of principle demonstration of a resonator that can switch from a high-Q “on state” to a low-Q “off state” at reduced temperatures is demonstrated in (Al1-xFex)2O3 and La(Al1-xFex)O3. The Fe3+ ions are in a high spin state (S=5/2) and undergo electron paramagnetic resonance absorption transitions that increase the microwave loss of the system. Transitions occur between mJ states with a corresponding change in the angular momentum, J, by ±ħ (i.e., ΔmJ=±1) at small magnetic fields. The paramagnetic ions also have an influence on the dielectric and magnetic properties, which I explore in these systems along with another low loss complex perovskite material, Ca[(Al1-xFex)1/2Nb1/2]O3. I describe what constitutes an optimal microwave loss switchable material induced from EPR transitions and the mechanisms associated with the key properties. As a first step to modeling the properties of high-performance microwave host lattices and ultimately their performance at microwave frequencies, a first-principles approach is used to determine the structural phase stability of various complex perovskites with a range of tolerance factors at 0 K and finite temperatures. By understanding the correct structural phases of these complex perovskites, the temperature coefficient of resonant frequency can be better predicted. A strong understanding of these parameters is expected to open the possibility to produce new types of high-performance switchable filters, time domain MIMO’s, multiplexers, and demultiplexers. / Dissertation/Thesis / Doctoral Dissertation Materials Science and Engineering 2020