New ferroelectrics for efficient microelectronics

When we communicate with others over wireless networks, information is sent to data centers where it is collected, stored, processed and distributed. As the use of renewable energy continues to grow, it is likely to become the leading source of energy consumption this century. In most modern computers, memory and logic are physically separated, so the interaction between these two components requires a lot of energy when accessing, processing and re-storing data.

A team of researchers at Carnegie Mellon University and Penn State University is investigating materials that could lead to the integration of memory directly on top of a transistor. By changing the architecture of the microcircuit, processors can be much more efficient and consume less energy. In addition to creating proximity between these components, research-based persistent materials have the potential to eliminate the need to regularly update computer memory systems.

Their latest works have been published Science studies materials that are ferroelectric or have a spontaneous electrical polarization that can be reversed by applying an external electric field. The recent discovery of wurtzite ferroelectrics, mainly materials incorporated into semiconductor technology for integrated circuits, enables the integration of new energy-efficient devices for applications such as non-volatile memory, electro-optics and energy harvesting.

One of the biggest challenges of wurtzite ferroelectrics is that the gap between the electric fields required for operation and the breakdown field is very small.

“Considerable efforts to increase this margin require a thorough understanding of the effects of the composition, structure, and architecture of the films on their polarization switching ability in practical electric fields,” said Sebastian Calderone, a Carnegie Mellon postdoctoral researcher. lead author of the article.

The two institutions joined together to collaborate on this research through the Center for 3D Ferroelectric Microelectronics (3DFeM), a program of the Energy Frontier Research Center (EFRC) led by Penn State University.

Carnegie Mellon’s Department of Materials Science and Engineering, led by Professor Elizabeth Dickey, was selected for this project because of its foundation in studying the role of materials structure in functional properties at the very small scale using electron microscopy.

“Professor Dickey’s group brings particularly relevant expertise in measuring the structure of these materials at very small length scales, as well as focusing on the specific electronic materials of interest in this project,” said John-Paul Maria, professor of materials science and engineering at Penn State University.

Together, the research team created an experiment that combined the two institutions’ strong expertise in the synthesis, characterization, and theoretical modeling of wurtzite ferroelectrics.

By observing and quantifying polarization switching in real time using scanning electron microscopy (STEM), the study has led to a fundamental understanding of how such new ferroelectric materials switch at the atomic level. As research in this field progresses, the goal is to expand the materials to a size that can be used in modern microelectronics.