PhD Position in Computational X-ray Imaging and Semiconductor Metrology — EPFL

Role overview

Mission The newly established Laboratory for Nanoscale X-ray Metrology is looking for a motivated PhD student to develop computational and experimental methods for high-resolution 3D imaging.

In this role, you will help establish new X-ray microscopy performance benchmarks by pushing the limits of imaging resolution and sample thickness achievable for semiconductor applications.

To achieve this, the project will focus on the following topics:

• Depth-of-Field Limitations: At 1 nm resolution, the depth of field shrinks to just a hundred nanometers, yet the high X-ray penetration allows imaging of samples that are several orders of magnitude thicker.

The project will develop an extended depth-of-field reconstruction framework for thick 3D samples.

• Mismatch Between Theory and Experiment: Reconstruction methods are based on idealized image formation models, which break down under extreme imaging conditions.

Achieving high-performance imaging requires improving the models and developing robust computational optimization algorithms, to account for issues such as experimental nanoscale vibrations.

• High-Performance 3D Imaging: Integrating these methods into tomography and laminography, and performing synchrotron-based experiments to visualize previously "unseen" features in modern semiconductor devices.

Main duties and responsibilities Project Description The performance of X-ray microscopy has improved significantly over the last decade, enabling synchrotron-based X-ray imaging to resolve individual transistors in modern semiconductor devices.

As semiconductor technology enters the new era of the 3D transistor, the need for non-destructive, high-resolution 3D imaging methods has never been greater.

While X-ray microscopy holds the potential for nanometer-scale defect detection in 3D semiconductor devices, its imaging performance requires further breakthroughs.