Today's RF devices, e.g. timing chips, consist of a Si substrate and different thin films stacked on top. Unfortunately these thin films typically contain electric charge, and thus, when deposited on top of the Si wafer, a harmful conductive surface layer is formed to the substrate. This conductive layer, also known as parasitic surface conductivity (PSC), causes distortion in the RF signals and should thus be avoided for optimal device performance. In this position the goal is to develop new solutions to mitigate the PSC-layer. Additionally new characterization methods for the PSC-layer properties are to be developed.

Microelectronics area: 1

Host location: Aalto University

Research Group: Electron Physics Group

Primary contact / supervisor: Hele Savin

In this position the aim is to develop fully CMOS-compatible sensors with close to ideal performance on inexpensive Ge-on-Si substrates. The idea is to utilize the superior Ge material properties such as high mobility and narrow band gap, yet simultaneously allowing CMOS circuits to be integrated into the same wafer (Si substrate). Novel gate oxide materials will be applied and special emphasis paid on the interface quality between oxide and Ge. Additionally new characterization methods for the Ge-on-Si substrates are to be developed.

Microelectronics area: 1

Host location: Aalto University

Research Group: Electron Physics Group

Primary contact / supervisor: Hele Savin

All devices in microelectronics utilize ohmic contacts between metals and semiconductors. Conventionally these contacts are achieved by ion implantation causing damage, recombination losses and requiring the use of high temperature adding complexity and material restrictions. In this position the aim is to study and develop novel methods for ohmic contact formation providing benefit to the whole semiconductor industry. After successfull experimental demonstration of proper ohmic contacts, the ultimate goal is to integrate the developed concepts and methods into actual devices.

Microelectronics area: 1

Host location: Aalto University

Research Group: Electron Physics Group

Primary contact / supervisor: Hele Savin

Development of next generation smaller and faster sensor chips is constrained by the limited data transfer rates within sensor and logic devices in a system. Advanced and emerging packaging technologies offer solutions to integrate MEMS and logic dies to realize system-in-package (SiP) thereby offering several advantages, such as reduced latency, increased design flexibility and reliability. This research work aims to combine two microfabricated platforms – 3D PiezoMEMS and solid-liquid-interdiffusion (SLID) bonding developed at Aalto University. 3D PiezoMEMS is an advance piezoelectric MEMS sensor capable of full 3D motion, whereas SLID is a wafer-level bonding technology with an advantage of reduced bonding temperature. The goal of the work is to demonstrate beyond state-of-the-art MEMS package with fast speed, high density interconnect solutions enabling sensor systems with increased intelligence.

Microelectronics area: 2

Host location: Aalto University

Research Group: Mervi Paulasto-Kröckel

Primary contact / supervisor: Mervi Paulasto-Kröckel

Aluminum nitride (AlN) and high-Al-content AlGaN are in the spotlight as materials for the next-generation wide band gap (WBG) devices. However, AlN-based vertical devices with ideal electrical properties have yet to be realized. A major technical challenge for these devices is achieving controlled conductivity across a broad range. Distributed polarization doping (DPD) has recently been proposed as a unique doping technology for nitride semiconductors. In this work the candidate will develop Metal-Organic Vapor Phase Epitaxy (MOVPE) deposition processes for single crystalline high Al-content AlGaN films and investigate distributed polarization doping (DPD) techniques for p- and n- doping. Goal of the work is to demonstrate DPD AlN p-n diode and POLFET.

Microelectronics area: 1

Host location: Aalto University

Research Group: Mervi Paulasto-Kröckel / VTT

Primary contact / supervisor: Mervi Paulasto-Kröckel

Carbon nanomaterials have gained high interest for bioelectrochemical applications like biosensors and biofuel cells related to excellent conductivities, well-established bio functionalization methods, and high surface area to immobilize a high number of biomolecules preserving accessibility for its substrate. Besides the huge varieties of different nanosized carbon structures, the principal materials used in this field are carbon nanotubes and graphene. Nanosized sp2 allotropes of carbon behave electrochemically almost the same as macroscopic carbon electrodes but the formation of porous structures provokes an extension of the electrode with drastically enhanced surface area. Interestingly, there are little quantitative studies about the effective enhancement of the electroactive surface using nanocarbon materials. In this work, the candidate will investigate nanostructured carbon deposition methods and the use of nanostructured carbon in bio-detectors.

Microelectronics area: 1

Host location: Aalto University

Research Group: Tomi Laurila / VTT

Primary contact / supervisor: Tomi Laurila

In this position you will develop and model CMOS circuits operating in the cryogenic temperatures. During the last years the interest towards low temperature CMOS circuits has increased because of activities both in quantum computing as well as non-terrestial communications and sensing. In this position you will design, model and measure CMOS circuits developed for RF, analog, mixed mode or digial domains depending on your interests. Additionally, we will engage your research to industrial operation within this field.

Microelectronics area: 2, 3

Host location: Aalto University

Research Group: Electronic circuit design

Primary contact / supervisor: Jussi Ryynänen

In this position you will develop elements for domain specific systolic array sensor processor accelerators for directed communications. These accelerators will be implemented together with RISC-V microprocessor for optimal energy efficiency-flexibility trade-off in implementation of signal processing. RISC-V and domain specific accelerators are timely research topic in microelectronics circuit design aiming for energy efficient implementations of circuits assisting machine learning and AI applications in energy-scarce operating environment.

Microelectronics area: 2, 3

Host location: Aalto University

Research Group: Electronic circuit design

Primary contact / supervisor: Jussi Ryynänen

Join us in revolutionizing IoT sensor platforms with next generation neuromorphic audio-inference integrated circuits (ICs)! This PhD project focuses on surpassing state-of-the-arts in power efficiency, latency, and neural network accuracy by leveraging advanced time-domain processing techniques. As a researcher, you will design, implement, and verify analog/mixed-signal ICs for audio-inference tasks like keyword spotting, with opportunities for multiple tape-outs. You are expected to have backgrounds in transistor-level analog circuit design, with experience in digital hardware design and PyTorch-based neural networks as a plus. Shape the future of AI-driven IoT devices with us!

Microelectronics area: 2, 3

Host location: Aalto University

Research Group: Electronic circuit design

Primary contact / supervisor: Jussi Ryynänen

In this topic you will participate on developing a 5G FR3 transceiver for full-duplex and narrow band-separation frequency-duplex systems. Transmission leakage to reception is a major obstacle in transceivers for such systems. Hybrid self-interference cancellation at both analog and digital domain is a remedy for this issue, but it comes with a penalty of low reception sensitivity. Major challenge for analog self-interference cancellation is the additional noise it introduces for reception. We are developing a method to introduce noise-cancelling scheme to mitigate the issue. In this work you will join an international team that is closely co-operating will some major industrial players.

Microelectronics area: 2, 3

Host location: Aalto University

Research Group: Electronic circuit design

Primary contact / supervisor: Jussi Ryynänen

Energy efficiency of modern power drives on IGBT and GaN technologies can be further boosted with intelligent control circuitry. In this position you will develop both analog and digital CMOS circuits that will tune the operation of the high power devices. The tasks range from device-level studies of the imperfections of the power devices up to development of control algorithms, even powered by AI. This task is closely related to industrial collaboration.

Microelectronics area: 1, 2

Host location: Aalto University

Research Group: Electronic circuit design

Primary contact / supervisor: Jussi Ryynänen

Circuit and electromagnetic co-design of active antennas. Active antennas integrate circuit components, such as amplifiers, mixers and filters in the radiating structure. Our aim is to avoid pre-defined interface and reduce losses, increase integration level and enable new features. We plan to integrate power amplifiers and low-noise amplifiers in an antenna element. Both amplifiers are biased on and off one at a time to realize Tx/Rx switch. Further, we plan to realize additional load-modulation amplifier in the same element for increased back-off efficiency. We will consider active circulators realized on the antenna element and study active impedance tuning methods to compensate for active impedance effects due to beam steering.

Microelectronics area: 1, 2

Host location: Aalto University

Research Group: Antennas and wireless sensors

Primary contact / supervisor: Ville Viikari

Integration of integrated circuits and electromagnetic structures. We consider different packaging and coupling mechanisms for integrated circuits and electromagnetic strucutres. We study if non-galvanic coupling can be used to realize RF connections. We also consider chip-integrated antennas and antennas-in-package. We study how to best combine electromagnetic and circuit simulations of the chip that is integrated with an electromagnetic structure.

Microelectronics area: 1, 2

Host location: Aalto University

Research Group: Antennas and wireless sensors

Primary contact / supervisor: Ville Viikari

Telecommunication algorithms accelerators related computer architectures (particularly considering this in the context of RISC-V cores); particularly MAC-layer level accelerators, including new dedicated commands and compilers for flexible use and implementation of such blocks in the product development.

Microelectronics area: 3, 4

Host location: Aalto University

Research Group: Networked Systems

Primary contact / supervisor: Petri Mähönen

Flexible on-silicon supported novel MAC-solutions that support multi-frequency and programmable MAC-structures. Work would include also consideration of interfaces, Programmability, and Compiler techniques -- vision would be to extend successful P4 concepts down to real-time MAC/PHY-interfaces considering on-silicon and Network-on-Chip concepts.

Microelectronics area: 3, 4

Host location: Aalto University

Research Group: Networked Systems

Primary contact / supervisor: Petri Mähönen

Applicant may propose a topic that 1) fits to the Aalto's scope of microelectronics research, 2) is well-justified with suffcient background, and 3) can be completed within three-year doctoral studies.

Microelectronics area: 1, 2, 3, 4

Host location: Aalto University