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THOMAS DEFFORGE - Ph.D. in Electronics

What is your professional / educational background and what is your Ph.D. Topic?
For my dissertation in electronics, I worked on manufacturing porous silicon layers by the anodization of silicon, a material used extensively in micro-electronics.In the present case, the objective was to etch holes (called via) through the silicon substrate and to fill these holes with a conductive material (copper). The etching of through via as well as filling them with an electrochemical copper deposit constituted the bulk of my work. Thus, it was possible to electrically connect both sides of a silicon chip using these conducting via. The engraving of through vias as well as filling them with an electrochemical copper deposit constituted the bulk of my work. In the end, the electrical characteristics of the through via conductors allowed us to verify the viability of this manufacturing process.

How has the Ph.D. process been for you?
My dissertation research took place mainly at the laboratory GREMAN (Materials, Micro- electronic, Acoustics and Nanotechnology Research Group) on the site of the company STMicroelectronics. I also had the opportunity to take advantage of the availability of means and equipment in order to do my work. But outside of that environment, these three years of research were very enriching. The project management which was left to me, the innovative research, and the interaction with my colleagues has meant that these 36 months have passed very quickly.

What have you learned from this experience?
Apart from the knowledge gained by writing a dissertation, these three years working in the same laboratory have allowed me to create relationships, professional and personal, with my colleagues. Some have become, after discussions, friends. What is more, this period has seen profound changes in our professional lives. From young students arriving at the laboratory, we finish our dissertation in front of a jury who recognizes our work. And in conferring the title of doctor, the jury validates our work, our effort and our knowledge.

What advice would you give to a student who was considering a Ph.D.?
A deep interest in scientific research is an indispensable prerequisite in order to develop professionally during a dissertation. If this interest is not present, do not take the step and start a Ph.D.

What are you doing now?

I am still working at the GREMAN laboratory with a post-doctoral contract. My work now continues my dissertation, that is, studying the electrochemical engraving of silicon in order to make porous silicon.