Magnetic nanocomposites could help shrink the components that power computer chips
When you think about making computer chips better, you probably think about transistors. My colleagues and I focused on a less visible part of the problem: the components that deliver power to those transistors. A chip needs ...
In our study, we fabricated these devices using a composite of nickel and iron oxide nanoparticles. Our measurements showed more than twice the inductance of comparable devices without a magnetic core. The broader question behind this work is how to bring useful magnetic materials into the small structures used in semiconductor manufacturing.
The research was conducted at the University of Florida with my coauthors Brenden M. Mears, Noah Morgan, Jennifer S. Andrew and David P. Arnold. Our study, now published in the Journal of Micromechanics and Microengineering, brought together expertise in materials synthesis, microfabrication and electrical characterization.
Why chips need tiny magnetic components
Voltage regulators convert an incoming electrical supply into the voltage a circuit needs. In many switching regulators, an inductor temporarily stores energy in a magnetic field and helps control changes in current. Together with other components, it turns rapidly switched electrical power into a steadier supply.
Inductors can be difficult to shrink. Reducing their dimensions generally reduces the inductance available from a particular design. One way to compensate is to add magnetic material around the conductor. That material changes how magnetic flux develops, allowing a compact structure to provide more inductance.
Illustration of eddy current formation: (a) bulk metal with strong eddy currents, (b) laminated metal structure showing reduced eddy currents and (c) magnetic nanocomposite with embedded nonconductive particles in the metal matrix, significantly suppressing eddy currents. Credit: Sai Pranesh Amirisetti
Comparison of the reported AC performance of integrated microinductors in terms of inductance density (x-axis) and peak quality factor, Qpeak. Credit: Sai Pranesh Amirisetti