The start of a promising career
Marie Merlin first entered the world of science through chemistry and biology, earning a bachelor's degree from the University of Grenoble Alpes. She continued her studies at the École Nationale Supérieure des Mines de Nancy, where she specialized in industrial engineering and materials science.
After an internship at CEA-Leti in 2022, Marie chose to return to complete her thesis. Attracted by the diversity of skills and technologies, she saw it as an opportunity to explore her research topic from several angles, in close connection with industrial realities.
Since October 2024, Marie has focused her research on titanium silicide, a compound obtained from a reaction between titanium and silicon. Her ultimate goal is to integrate this compound into new-generation, low-power FD-SOI transistors, a cutting-edge technology in the field of semiconductors.
At the MAM conference, she presented a poster on the relationship between phosphorus doping and titanium silicidation. The jury was impressed by the quality of her work, all the more remarkable given that she has just started her thesis. Marie won the prize for best poster:
“I didn't go there with the idea of winning a prize. I was mainly keen to present the results of several months of intensive work in the laboratory," she says, still delighted with the award. “I really appreciated the intimate format of the poster presentations, with direct discussion."
Towards ever more efficient FD-SOI transistors
The challenges addressed in Marie's thesis are both technical and strategic. Today, two major families of transistors coexist: FinFETs and FD-SOI.
“I am seeking to transfer the advantages of titanium silicide, already integrated into FinFETs, to FD-SOI technology," she explains, “in particular to reduce processing temperatures and thus enable miniaturization, while maintaining good electrical performance."
While FinFETs already use titanium silicides (TiSiₓ) to ensure low contact resistivity, FD-SOI still relies mainly on nickel-based alloys (Ni(Pt)Si).
The introduction of titanium into FD-SOI architectures raises several challenges, particularly in terms of thermal and structural stability, in relation to the stability of the phases formed. Marie's goal is to achieve an optimized structure with a single interface in order to minimize specific contact resistance. This involves studying several aspects: metallization, heat treatment, and surface engineering.
The initial results she presented show that by doping silicon layers, it is possible to modify the diffusion of silicon in titanium. “Using existing samples and analyses, I essentially carried out data characterization and interpretation work," adds Marie, emphasizing the importance of the support she received from her colleagues in the laboratory.
A thesis serving tomorrow's technologies
Her research actively contributes to the major objectives of the FAMES pilot line, a European initiative that aims to strengthen the EU's semiconductor capabilities and ensure its technological sovereignty.
One of the building blocks of this initiative focuses on the industrialization of advanced technologies on FD-SOI substrates for applications in telecommunications, automotive, and smart devices. More specifically, this breakthrough is contributing to the development of 5G smartphones and 6G networks, radars and lidars for autonomous vehicles, and components for embedded artificial intelligence.