Phase field modeling of grain evolution in advanced nano-interconnects

Metal interconnects handle power and signal distribution in electronic circuits between transistors and to the outside world.  To enable the performance gains of the whole circuit, the width of these interconnects need to shrink to below 10nm in the coming decades.

Where Cu has been the dominant metal of choice for wider nano-interconnects, its resistivity it too high for such small dimensions. Alternative interconnect metals such as Ru, Mo or alloys are actively being researched.

Key performance metrics for such new materials are their resistivity and mechanical properties in small dimensions. These metrics are strongly driven by the structure of their grains.

Understanding grain evolution in advanced nano-wires is thus crucial for the development of advanced semiconductor technologies.

During this PhD, phase field and related models need to be developed and employed to perform in-depth studies of the grain evolution in extremely scaled nano-interconnects, where, amongst others, time evolutions, temperature dependencies, effects of initial grain sizes, shapes and arrangements and interface, grain boundary and bulk contributions will be studied for the so-called “alternative metals” explained above. Where needed, experimental data to validate the models will be provided and eventually need to be collected by the student. The main aim of the PhD is to understand the experimentally provided data and to predict grain evolutions outside the experimental domain.