Modern semiconductor devices require precise control over dopant concentration and position, which can be achieved through ion implantation followed by careful annealing. Photo-Modulated Reflectivity (PMR) measurement is a widely used technique for monitoring implantation dose on as-implanted, pre-annealed blanket and production wafers.

The PMR system uses two laser beams: a periodically modulated pump beam induces changes in the reflectivity of the irradiated area, while a probe beam measures these changes. The lasers operate at different wavelengths, allowing the reflected beams to be separated. Periodic variations in the intensity of the reflected probe beam, caused by changes in the reflectivity of the sample, are measured using a lock-in amplifier. This measurement method requires high-precision optical system and sophisticated electrical signal processing.

The PhD candidate is expected to improve the stability and dose sensitivity by extending the laser wavelengths into the UV range and developing measurement protocols with variable illumination parameters. Microscopic changes from ion implantation as well as charge carrier dynamics and heat diffusion in Si and SiC, will be simulated. Finally, macroscopic optical properties need to be modeled.

The candidate will contribute to these tasks through a combined effort in instrument development, measurements on semiconductor samples, and theoretical modeling related to the PMR technique. The PhD work will be carried out in cooperation with Semilab Ltd. To further increase the potential of this methodology, other measurement techniques available in the company’s extensive equipment portfolio should be utilized.