Public defence in Electronics integration and reliability, M.Sc. Fahimeh Emadi

The title of the thesis: Contact Metallization Design for Low-Temperature Interconnects in MEMS Integration 

Thesis defender: Fahimeh Emadi
Opponents: 
Dr. Hermann Oppermann, Fraunhofer Institute für Zuverlässigkeit und Mikrointegration IZM, Berlin, Germany
Prof. Heli Jantunen, University of Oulu
Custos: Prof. Mervi Paulasto-Kröckel, Aalto University School of Electrical Engineering, Department of Electrical Engineering and Automation

Electronics, from smartphones to smart cities, demand smaller, faster, and more efficient devices, driving advances in packaging and interconnects. This thesis focuses on 1st-level interconnects, which connect components within the first packaging level in advanced packaging. These interconnects must support miniaturization, low temperatures, and stable microstructures while meeting application-specific requirements, with Micro-ElectroMechanical System (MEMS) devices as the focus of this work due to their widespread use. Cu-Sn Solid-Liquid Interdiffusion (SLID) interconnects are promising for 1st-level interconnects in MEMS but face challenges such as high temperatures and integration issues from wet chemical processes during Cu and Sn deposition on delicate MEMS wafers. This dissertation addresses these challenges by employing Co metallization with Cu-Sn interconnects and replacing Sn with Sn-In. The Cu-Sn-In/Co system achieves low-temperature, void-free bonding with excellent mechanical, thermal, and thermomechanical reliability for MEMS-IC integration.

Thesis available for public display 10 days prior to the defence at: https://aaltodoc.aalto.fi/doc_public/eonly/riiputus/

Contact:

Doctoral theses in the School of Electrical Engineering: https://aaltodoc.aalto.fi/handle/123456789/53