PhD - Leuven | More than two weeks ago
In the last decade, oxide semiconductors have emerged as a higher performance replacement for standard amorphous silicon thin-film transistors (TFT’s) in display back-plane and flexible electronics. Among different material candidates, Indium-Gallium-Zinc Oxide (IGZO) is the most promising, providing high performance with large area uniformity, low off-currents and low-temperature processing. As a result of the exceptional electrical characteristics of this material, it is envisaged to use it in applications where standard Silicon technology cannot be employed due to process temperature constraints (power gating in the Back-End of Line) or has fundamental limitations such as leakage current (selector transistors in DRAM arrays).
However, the long-term reliability of IGZO devices is one of the most important aspects to be still fully characterized and understood before full deployment. The aim of this PhD research is hence to study the overall IGZO TFT electrical reliability, targeting both logic and memory applications. To this end, this novel device must be fully characterized and modelled, from which fundamental understanding and possible reliability limitations are extracted, allowing for further process optimization and eventually the employment of these devices in real products. The PhD student will play a key role in understanding the device degradation by combining electrical characterization and modelling. Electrical characterization will take place within imec labs, in which the student will be responsible for developing his measurements routines and analyzing the subsequent measured data. The empirical activity will be followed by a fundamental modelling study. The student will model the defect generation and simulate the degraded devices using state-of-the-art device simulators. All the degradation mechanisms will be integrated within a comprehensive physics-based simulation framework which will be calibrated over a wide range of stress conditions. This approach is expected to shed light on physical mechanisms behind degradation of IGZO transistors and provide unprecedented accuracy for reliability modeling. The student will therefore be able to develop a solid measurement/characterization expertise, but also a deep understanding of the device degradation at the atomistic level.
The student will closely work with the device process engineers to enhance the device reliability, with the ab-initio modelling team to model the degradation in semiconducting oxides at the microscopic scale and with the reliability team to develop and apply electrical characterization routines and subsequent data analysis and modelling.
The applicant should have in-depth knowledge in the field of semiconductor/semiconductor device/solid-states physics, good programming skills (Python, Matlab, Perl and/or C/C++), eagerness to obtain exciting results and learn. Within this multiscale cross-disciplinary project, the PhD student will be part of a large imec group working in collaboration with industrial partners and therefore a team player spirit is fundamental.
Required background: MS degree in physics, electrical/material engineering
Type of work: 60% experimental, 40% modelling
Supervisor: Ingrid de Wolf
Daily advisers: Adrian Chasin / Stanislav Tyaginov
Required background: Electrical Engineering, Materials Engineering, Physics
Type of work: 60% experimental, 40% modeling
Supervisor: Ingrid De Wolf
Daily advisor: Adrian Vaisman Chasin, Stanislav Tyaginov
The reference code for this position is 2021-012. Mention this reference code on your application form.