Surface-dependent adsorption and diffusion processes in area-selective deposition of ruthenium

Promovendus/a: Jacobus Soethoudt

Promotor(en): Prof. dr. Annelies Delabie

Electronic devices have an ever-increasing role in our daily lives: they allow us to communicate with each other, provide our entertainment, and make our work and life convenient in myriad ways. This evolution is enabled largely by the creation of electronic devices which are faster, more power-efficient, and increasingly versatile. These improvements are possible by making the basic building blocks of these devices smaller and smaller, which allows us to put more blocks on a single microchip, and to connect them in more efficient ways. Building blocks are currently placed on top of each other by ultra-precise robotic positioning systems. When we make each block smaller and smaller however, this positional alignment becomes increasingly difficult and this approach now reaches its limits.

Area-selective deposition (ASD) is therefore proposed as an alternative approach to place a material only where it is desired. ASD makes use of material deposition processes which can distinguish the area where material deposition is needed, called the ‘growth area’, in contrast to the ‘non-growth area’ where no deposition is needed. By relying on physical and chemical processes which proceed in different ways or at different rates depending on the surface with which they interact, this approach could allow us to place materials only where they are needed.

This thesis investigates the surface dependence of physical and chemical processes involved in the deposition of ruthenium, which is of interest for several applications such as electronic devices and energy production. By determining how rapidly ruthenium is deposited on different surfaces, and how ruthenium behaves on the surface after deposition, this thesis facilitates the development of area-selective ruthenium processes for a variety of relevant technologies.