Empa Young Scientist Fellowship: Young researcher investigates tiny fractures with major consequences

A significant portion of our electronics is based on thin films. Nanometer-thin layers of semiconductors and other materials enable sensors, screens, capacitors, batteries, transistors, and much more. Advances in thin-film technologies have also enabled the increasing miniaturization of electronics. As a result, everyone today carries a device in their pocket that far outperforms the room-filling supercomputers of the 1980s.

These tiny components offer many advantages - but also present certain challenges. "For instance, transistors contain layers of silicon oxide and hafnium oxide that are only a few nanometers thick and stacked on top of one another", explains Empa researcher Vivek Devulapalli. "When such a device fails, it's often very hard to tell whether a mechanical cause is to blame, because we still know very little about how these films crack, delaminate, or deform." Devulapalli aims to improve our understanding of these nanoscale mechanics in a research project, for which he has received a two-year Empa Young Scientist Fellowship.

Devulapalli, a postdoctoral researcher in Empa's Laboratory for Mechanics of Materials and Nanostructures in Thun, will focus on multilayer thin films of metal oxides. This large family of materials encompasses substances with a wide variety of optical and electronic properties. "Metal oxides are very frequently used in thin-film technology for their functionality," says Devulapalli. "But right now, their mechanical properties right down to the atomic scale are poorly understood."

Tracking the tiniest deformations in real time

The oxide films the young researcher wants to study are amorphous, meaning they don't form a regular crystal lattice. In a previous research project, Devulapalli discovered that certain types of multilayered oxide thin films exhibit better plasticity than monolithic - i.e. single-layer - films of the same materials. This allows the multilayers to deform without cracking fatally - which is good news for the highly complex, miniaturized electronic components made from such layers.

In his new research project, called MOSAIC, Devulapalli aims to further investigate the nanomechanics of multilayer thin-film systems made of different metal oxides. The mechanical characterization of such tiny components is complex. To address this, the researcher is using advanced microscopy methods such as in situ straining and 4D-STEM, or four-dimensional scanning transmission electron microscopy. "We want to observe our samples in real time as we strain them, thereby gaining a detailed understanding of the development of cracks and other mechanical faults," explains Devulapalli.

For his experiments, Devulapalli intends to start with model systems made of well-known oxide materials, such as silicon oxide and aluminium oxide. "My goal is to understand how different parameters - such as composition, density, and layer thickness - influence the mechanical properties of the multilayer system," the researcher explains. "Once we understand the fundamentals, we may be able to determine how to make such systems mechanically more robust in the future."

To the press release

Talent promotion at Empa

The Empa Young Scientist Fellowship is a funding program for exceptionally talented young scientists. Fellows receive funding to carry out an independent research project for a period of two years. Fellowships are awarded in a competitive process to select the most promising projects.

Further information

Dr. Vivek Devulapalli
Empa, Mechanics of Materials & Nanostructures
Phone +41 58 765 63 98
[email protected]

• Education, Research & Innovation
• Education, Research & Innovation: Science promotion