PhD - Leuven | Just now
As the semiconductor industry pushes the boundaries of Moore’s Law, the need for ultra-precise, non-destructive metrology becomes more urgent than ever. Shrinking feature sizes, complex 3D architectures, and the rise of hybrid bonding demand inspection tools that can see deeper, sharper, and faster — without damaging the device.
This PhD project offers a unique opportunity to redefine the future of semiconductor inspection by advancing Gigahertz Ultrasound Microscopy (GUM) — a cutting-edge technique that uses ultra-high-frequency sound waves to image materials at sub-micron and even nanometer scales.
Traditional metrology tools like optical microscopy and AFM are hitting their limits. GUM, on the other hand, offers the ability to probe sub-surface features with nanometer-level precision, overcoming some of the limitations of optical diffraction and providing deeper penetration into semiconductor materials. Its acoustic nature allows it to map mechanical properties like elasticity, density, and layer thickness, providing crucial insights into the structural integrity and quality of semiconductor devices at the nanoscale. Today, its low-frequency counterpart, i.e. Scanning Acoustic Microscopy (SAM), has become the reference technique for void detection and hence turned into a critical inspection technique for 3D integration and bonding applications. However, its detection limit is being challenged as the hybrid bond pitch scales down. We foresee GUM to become an indispensable tool for ensuring reliable production in future semiconductor technologies as sub-µm voids turn into killer defects in bonded wafer pairs — but current systems are too slow and limited for industrial deployment.
This project aims to break through those barriers by:
What you’ll gain
Required background: Engeering Technology, Engineering Science
Type of work: 10% literature, 40% modeling+design, 50% characterization
Supervisor: Xavier Rottenberg
Co-supervisor: Claudia Fleischmann
Daily advisor: Grim Keulemans
The reference code for this position is 2026-144. Mention this reference code on your application form.