In order to enable the next generation of communication systems (5G, 6G), the circuits are getting more complex than ever and are composed today of several chips, each implemented in different technologies optimized for a specific function. Downscaling of CMOS technology has allowed the integration of high-speed transceivers on Silicon chips, but power amplifiers using III-V technologies, and high-performance switches fabricated on SOI substrates remain the preferred choice for RF Front-End circuits. In order to develop cost and power efficient RF systems, co-integration of these different devices becomes critical.
The current research in imec for RF front-end module technologies focusses on (i) the integration of high-speed III-V and III-N devices on a Si platform; and on (ii) the co-integration of these device architectures with standard Si CMOS. In that context, it is critical to optimize the technology considering not only the electrical but also the thermal aspects, given the large amount of energy dissipated by power amplifiers.
In this PhD, you will contribute to solve this challenge by:
- Assessing the effect on RF figures of merit of the different interfaces created by advanced integration. These non-ideal interfaces are expected to present fixed charges and traps causing RF losses and non-linearities as well as frequency dependent phenomena.
- Investigating the thermal behavior of active devices when confined in a 3D system with the presence of high-power GaN devices. In these complex systems, thermal paths are affected by the proximity of other devices generating heat in all spatial directions (especially vertically).
Required background: Candidates are expected to have a Master’s degree in Engineering Science with a strong interest in RF/microwave techniques as well as semiconductor physics.
Type of work: 45% modelling, 40% experimental, 15% literature
Supervisor: Jean-Pierre Raskin
Daily advisor: Bertrand Parvais
The reference code for this position is 2020-045. Mention this reference code on your application form.