Department of Electrical Engineering and Automation

Electronics integration and reliability

The research in the Electronics Integration and Reliability (EILB) is focused on new materials, three-dimensional (3D) integration and reliability of electronics and microelectromechanical systems (MEMS). The material concepts and technologies we develop will be of central importance in the realization of almost any ubiquitous electronics and miniaturized smart systems in applications from minimally invasive surgery to autonomous driving.
Electronics integration and reliability

EILB group is located in Micronova ( and uses the cutting-edge infrastructure of OtaNano, providing centralized access to advanced nanofabrication, nanomicroscopy and low-noise measurement facilities. In addition, the group has its own reliability testing laboratory including equipment for environmental, mechanical and thermomechanical testing, and uses different modeling tools to anticipate and rationalize reliability performance of heterogeneous integration in micro- and nanosystems.

The intensive co-operation of EILB with numerous semiconductor, electronics and MEMS manufacturing companies facilitates the comprehensive training of our students to combine scientific knowledge with industry-relevant technological advancement.

Examples of our recent research from large international Public-Private-Partnership projects are ENIAC Lab4MEMS II, ECSEL Informed and ECSEL POSITION II.

ENIAC Lab4MEMS II, Micro-Optical MEMS, micro-mirrors and pico-projectors: One of the main objectives of this project was to develop a fully integrated process for wafer level MEMS packaging utilizing Poly-Si through silicon via (TSV) capped MEMS devices. Sc. “vias before bonding” capping process and contact metallizations for Poly-Si TSVs (see Fig. below) were developed together with VTT and industrial partners (Okmetic and Murata Finland). Then the process integration was demonstrated by using piezoelectrically driven MEMS actuators.

Fig. 1a
Fig. 1a)
Fig. 1b
Fig. 1b)

Figure 1a) and 1b). SEM micrographs of the fully integrated MEMS package including Al redistribution layer, Cap wafer poly-Si TSVs, and wafer level SLID bonding providing electrical interconnection between the device and cap wafer as indicated by the SEM-EDS elemental analysis

ECSEL InForMed, An Integrated Pilot Line for Micro-Fabricated Medical Devices: The project covered development, assembly and fabrication of smart catheters and other minimally invasive diagnostic and therapeutic instruments and tools. The focus of the research in EILB was in development of advanced bonded silicon-on-insulator (SOI) structures for flexible sensor assemblies.

ECSEL POSITION II Towards the next generation of smart catheters and implants: Miniaturized MEMS sensors and transducers using advanced materials are studied in this project to realize smart catheters. EILB group studies the structural stability of different piezo-films, alternative piezo/electrode material stacks and Piezoelectric Micromachined Ultrasonic Transducers (PMUT) devices.

Recent doctoral dissertations from the EILB group include “Solid-liquid interdiffusion bonding for MEMS device integration” by A. Rautiainen and “Quality, Microstructural Refinement and Stability of Atomic-layer-deposited Aluminum Nitride and Aluminum Oxide Films” by M. Broas

Our teaching is part of the major Translational Engineering of AEE program, and includes e.g. the following courses:

  • ELEC-E8712 Design for Reliability
  • ELEC-E8713 Materials and Microsystems Integration
  • ELEC-E8714 Sustainable Electronics
  • ELEC-E8711 Materials Compatibility

For more information, please contact prof. Mervi Paulasto-Kröckel ([email protected]), senior lecturer, Dr. Vesa Vuorinen ([email protected]) or doctoral candidate Mr. Glenn Ross ([email protected]).


Group members

Latest publications

Effect of crystal structure on the Young's modulus of GaP nanowires

Prokhor A. Alekseev, Bogdan R. Borodin, Pavel Geydt, Vladislav Khayrudinov, Kristina Bespalova, Demid A. Kirilenko, Rodion R. Reznik, Alexey Nashchekin, Tuomas Haggren, Erkki Lahderanta, George E. Cirlin, Harri Lipsanen, Mikhail S. Dunaevskiy 2021 Nanotechnology

Characterization of AlScN-Based Multilayer Systems for Piezoelectric Micromachined Ultrasound Transducer (pMUT) Fabrication

Kristina Bespalova, Elmeri österlund, Glenn Ross, Mervi Paulasto-Kröckel, Abhilash Thanniyil Sebastian, Cyril Baby Karuthedath, Stefan Mertin, Tuomas Pensala 2021 Journal of Microelectromechanical Systems

Calculation of Phase Diagrams and First-Principles Study of Germanium Impacts on Phosphorus Distribution in Czochralski Silicon

Hongqun Dong, Xiaoma Tao, Mervi Paulasto-Kröckel 2021 Journal of Electronic Materials

A humidity-induced novel failure mechanism in power semiconductor diodes

J. Leppänen, G. Ross, V. Vuorinen, J. Ingman, J. Jormanainen, M. Paulasto-Kröckel 2021 Microelectronics Reliability

Wafer Level Solid Liquid Interdiffusion Bonding

V. Vuorinen, H. Dong, G. Ross, J. Hotchkiss, J. Kaaos, M. Paulasto-Kröckel 2021 Journal of Electronic Materials

Atomic layer deposition of AlN using atomic layer annealing - Towards high-quality AlN on vertical sidewalls

Elmeri Österlund, Heli Seppänen, Kristina Bespalova, Ville Miikkulainen, Mervi Paulasto-Kröckel 2021 Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films

Stability and residual stresses of sputtered wurtzite AlScN thin films

Elmeri Österlund, Glenn Ross, Miguel A. Caro, Mervi Paulasto-Kröckel, Andreas Hollmann, Manuela Klaus, Matthias Meixner, Christoph Genzel, Panu Koppinen, Tuomas Pensala, Agnė Žukauskaitė, Michal Trebala 2021 Physical Review Materials

Temperature Stability of Electrode/AlScN Multilayer Systems for pMUT Process Integration

Kristina Bespalova, Glenn Ross, Mervi Paulasto-Kröckel, Abhilash Sebastian Thanniyil, Cyril Karuthedath, Stefan Mertin, Tuomas Pensala 2020 Proceedings of the IEEE International Ultrasonics Symposium, IUS 2020

Study of Cu-Sn-In system for low temperature, wafer level solid liquid inter-diffusion bonding

Joseph Hotchkiss, Vesa Vuorinen, Hongqun Dong, Glenn Ross, Jani Kaaos, Mervi Paulasto-Krockel, Tobias Wernicke, Anneliese Ponninger 2020 Proceedings - 2020 IEEE 8th Electronics System-Integration Technology Conference, ESTC 2020

Where is silicon based MEMS heading to?

Mervi Paulasto-Kröckel, Markku Tilli, Glenn Ross, Heikki Kuisma 2020 Handbook of Silicon Based MEMS Materials and Technologies (Third Edition)
More information on our research in the Research database.
Research database
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