Throughout the previous decades ever faster, smaller and cheaper electronic devices have revolutionized our life. The main driving force behind this has been the continuous device scaling. However, the further device scaling has been led serious increase of its manufacturing cost. Heterogeneous integration can open up the opportunity of three dimensional devices with vertical integration. Not only the expected performance, there is a huge future extensibility in heterogeneous devices by using these vertical stackings. One of the key challenges in this integration is to connect different components by bonding or stacking, with minimum interconnection pitches. On top of that, low thermal budget is a key aspect to look into due to the temperature limitations of various device types to be integrated.
In order to achieve a robust bonding method with low temperature processes, direct bonding has been utilized in a number of applications. Plasma activated direct bonding enables us to obtain a sustainable bonding solution b
y using inorganic dielectric layers with proper surface preparation. In addition, metal/dielectric “hybrid” bonding is attractive because it provides mechanical and electrical connection simultaneously. In order to precisely implement tailored surface treatment and bonding processes for specific applications, deep understanding of interfacial bonding mechanisms is required. In particular for hybrid bonding, it requires accumulation and utilization of knowledge for material science.
The offered PhD position will put you in a highly challenging circumstance, where you will be involved state of the art in bonding process development with deep insight in material science. In particular, you will investigate layer transfer processes, bonding mechanisms of metals, dielectrics, III-V, and IV, by using several characterization methods of surface and interface analysis. The impact of plasma activation on surface/sub-surface on the different materials (e.g. alternative dielectrics, metals, etc...) will be investigated to achieve low temperature bonding. The obtained knowledge will be applied onto device characterization as the proof of the concept.
- High quality research focusing on heterogeneous integration, which include die-to-wafer, wafer-to-wafer and advanced packaging
- Investigation of bonding mechanisms for development of innovative concepts of bonding/stacking system.
- Gaining deep insight from understanding of bonding mechanisms, which can be expandable for any material science.
- Publishing and presenting results both at international conferences and in scientific journals
Required background: materials science and engineering, mechanical engineering
Type of work: 50 % experimental work, 25 % technology study, 25 % literature
Supervisor: Stefan De Gendt
Daily advisors: Lan Peng, Alain Phommahaxay, Fumihiro Inoue
The reference code for this PhD position is STS1712-40. Mention this reference code on your application form.