STAY2ME · Silicon Through holes by Accumulative interplaY of 2 Micron short pulsEs

At a time when digitalization is omnipresent in our daily lives and silicon-based devices remain a key factor, the demand for high-density interconnections and increasingly compact, reliable electronics is essential for the continued advancement of semiconductor technologies. Through-Silicon Vias (TSV), the vertical interconnects that make true 3D integration possible in CMOS chips, MEMS sensors, and AI hardware play a key role. The STAY2ME project lays the foundation for a radical shift in how silicon structures that drive tomorrow’s technologies can be shaped and connected. Our radically innovative laser-based technology enables non-contact, chemicals-free, high-aspect-ratio micro-drilling within silicon, delivering unprecedented precision without detrimental side-effects in the surrounding material. This will be a game-changer for fabricating TSV. At the core of this innovation is a mJ-energy class laser operating at 2 micrometers in the novel GHz-burst regime, where a rapid train of pulses is delivered in ultrashort bursts. This laser combines the right wavelength with the right pulse dynamics, achieving nonlinear absorption and how energy accumulates in silicon-thus avoiding the laser beam distortion and chaotic energy deposition that plague existing methods. It could outperform the precision, speed and sustainability of Deep Reactive Ion Etching, today’s state-of-the-art for TSVs, and transforms what was once a materials limitation into a design revolution. Understanding and controlling how such a laser interacts with silicon is a breakthrough, opening a fundamentally new regime of laser-based silicon processing which offers unprecedented control over the drilling process. One of the unique strengths of this project lies in its interdisciplinary consortium, bringing together specialists from physics, chemistry, electrical and mechanical engineering, and thus, covering all facets and know-how to successfully carry out the STAY2ME project.