Nanostructured porous materials form Micro- and nano-electronics applications

This thesis work presents new research on porous silicon technologies for the heterogeneous integration on silicon platforms, as a key enabling technology for future 3D integrated systems. Porous silicon can be obtained with CMOS compatible processes on localized area on silicon wafer and, due to its tunable electrical, mechanical and thermal characteristics is an effective buffer material. Moreover, macroporous morphologies of porous silicon can can be exploited for the realization of “bed-of-nails” type through wafer interconnects, paving the way to high density, low-cost, through silicon vias. This work is divided in three parts: the first part introduces porous silicon, summarizes the available literature and presents process characterization for the porous layers obtained in this work and their properties; the second part describes the layer transfer technology and the buried cavities technologies developed in this work using the porous layers presented in the previous part; the last part introduces two applications of the layer transfer technology: compliant contacts and integrated physically small antennas

FOSS CAD for the compact Verilog-A model standardization in Open Access PDKs

The semiconductor industry continues to grow and innovate; however, companies are facing challenges in growing their workforce with skilled technicians and engineers. To meet the demand for well-trained workers worldwide, innovative ways to attract skilled talent and strengthen the local semiconductor workforce ecosystem are of utmost importance. FOSS CAD/EDA tools combined with free and open-access PDKs can serve as a new platform for bringing together IC design newbies, enthusiasts, and experienced mentors

Design and technology for 3D MEMS device for vibration energy harvesting

In this work we present a new concept of a threedimensional vibration power generator made by micro-electromechanical systems (MEMS) technology, which can convert electric energy through transverse mode piezoelectric effect. The presented power generator is based on a long, thick-film, piezoelectric beam configured as a conical helical spring structure. The controlled release metal layer (CRML) MEMS technology has been used to realize the structure from photolithography-defined pattern on a silicon wafer. The advantage of CRML technology is the high repeatability and resolution and its compatibility with back-end of line (BEOL) processes of the integrated circuit (IC) industry. The purpose of the helical structure is also to combine the piezoelectric generator with a conical-helical antenna for RF applications in low-power, autonomous sensors network. The novel construction process of the piezoelectric generator and its structure are presented with finite element method (FEM) simulations to determine its resonant frequencies. This energy-harvesting structure is made enclosing a piezoelectric material between two metal layers. The presented structures operate, as antenna, in the 55-85 GHz frequency band and resonate with mechanical vibrations in the kHz region. These two characteristics are the ideal components for the deployment of miniaturized battery-free low-cost sensors in the emerging 60 GHz band and energy harvesting for power supply