In a recent development, researchers at the University of South Florida developed a new approach to alleviate electromigration in the nanoscale interconnect of electronics that are ubiquitous in state-of-the-art ICs. The initiative involved coating interconnects of copper with hexagonal boron nitride – a thin insulating two-dimensional material in terms of atomic configuration. The material shares structure similar to the wonder material graphene.
In electrochemical structures, electromigration is the phenomenon wherein an electrical current passes through a conductor to cause erosion of the material at atomic scale. To address this, conventional semiconductor technology uses a barrier or liner material. This, however, takes precious space on the wafer that could otherwise be used to fit in more transistors. Using the world’s thinnest possible two-dimensional materials, the goal is accomplished by the research team.
“With this development, it introduces new research opportunities for interfacial interactions between metals and angstrom-level 2D materials. Improvement in the performance of semiconductor and electronic devices is only one aspect of the result of the research. Furthermore, the findings of the study opens up new possibilities for the advancement in the manufacture of semiconductors and integrated circuits.”
Using a single layer of hBN as the barrier material, the novel encapsulation strategy further enables scaling of device density and progressions of Moore’s Law. For reference purpose, a nanometer is 1/60,000 the thickness of human hair, an angstrom is one-tenth of a nanometer. In fact, manipulating 2D materials of this thinness requires high level of precision and meticulous handling.
Meanwhile, in a recent study to validate the development, copper interconnects were inactivated with a monolayer of hBN through back-end-of-line.