The physics of growth

Growth is onw of my key areas of interest. The physics of growth comprises the mechanisms by which building blocks come together to form large scale structures in a way that is mainly dominated by local interactions and external fields. The role that these interactions have on determining the resulting structure is something that I have always found fascinating.

Growth is so ubiquitous that it can become almost invisible. Everything around us has been created at some point in time, and many technological advances have been enabled by our ability to control the way atoms are arranged to form materials with unique properties.

Growth under the influence of chemistry

One of the fundamental questions is to understand how growth conditions affect the microstructure of the materials that it is being formed. This is particularly interesting at low temperatures, where the mobility of atoms is hindered, potentially preventing them to relax and form highly crystalline materials. Under these conditions, the details of the processes taking place at the surface can strongly impact the resulting microstructure, in some cases leading to highly ordered structures and crystalline materials.

Developing the ability to predict how growth conditions lead to a certain microstructure can have a tremendous impact in our ability to grow new materials or for the scale up of lab scale processes. Therefore, it has a strong connection with advanced manufacturing. The control of surface reactivity can also impact the ability to achieve homogeneous materials or coat evenly high aspect ratio and nanostructured substrates, something that has fueled the development of 3D architectures in computer chips. It can also be used to develop new patterning strategies exploiting variations in reactivity between different materials to selectively grow in specific regions of the surface.

Combining models and experiments

My approach to these questions is to combine experiments and simulations to deepen our understanding of the fundamental aspects of thin film growth and develop new applications. From a experimental point of view, we focus primarily on a technique called atomic layer deposition, which has the advantage of being extremely reproducible -when done right. We also leverage synchrotron radiation and other in-situ techniques to probe in detail the structure of the material as they evolve from its individual atoms.

From a simulation perspective, our focus in mainly on kinetic Monte Carlo simulations to model growth on arbitrary graphs, as well as the development of novel simulation tools to model reactive transport and predict growth within high surface area materials. These allow us to translate our fundamental understanding to wafer and feature length scales that are relevant for advanced manufacturing applications.

And beyond

In addition to these areas, the physics of self-assembly, the early stages of the solar system, or the process of morphogenesis in biological systems are areas that I find fascinating. There is also beauty in growth, from the shapes of crystals and the landscapes sculpted by erosion, to the underlying models that help us connect the morphologies observed in vastly different systems.