In a examine printed in Nature Communications, a crew led by Penn State researchers developed a synthesis course of to provide a “rust-resistant” coating with additional options appropriate for creating sooner, extra sturdy electronics.
An extended-standing situation for future expertise is rust, which happens when oxygen and moisture react with iron-containing metals. Rust considerably reduces the lifespan and utility of parts in industries like automotive manufacturing.
In two-dimensional (2D) semiconductor supplies, which management electrical circulation in digital gadgets, oxidation presents an analogous problem. Whereas it is probably not termed “rust” within the semiconductor trade, corrosion can render these atom-thin supplies ineffective.
2D supplies are extraordinarily skinny, just one or just a few atoms thick. They present promise for superior semiconductors as a result of their thinness permits electrons to maneuver sooner and with much less resistance via the fabric. This, in flip, allows sooner and extra environment friendly digital efficiency.
Semiconductors are perfect for regulating electrical currents in digital gadgets as a result of they’ll conduct electrical energy beneath sure circumstances whereas appearing as insulators in others. This distinctive property makes them the foundational parts of digital gadgets, serving because the “brains” of pc chips.
One of many greatest points that we see in 2D semiconductor analysis nowadays is the truth that the supplies oxidize rapidly. You must guarantee their long-term reliability as a result of these are going into transistors or sensors which are imagined to final years. Proper now, these supplies do not final greater than every week out within the open.
Joshua Robinson, Research Co-Corresponding Writer and Professor, Supplies Science and Engineering, Pennsylvania State College
Conventional strategies to guard these supplies from rust contain oxide-based coatings, however these processes usually use water, which may paradoxically speed up the oxidation they intention to forestall. The crew sought a coating materials and methodology that would get rid of using water fully. This led them to amorphous boron nitride (a-BN).
Robinson added, “We wanted to get away from using water in the process, so we started thinking about what sort of 2D materials we can make that do not use water in its processing, and amorphous boron nitride is one of those.”
In line with Robinson, a-BN, a non-crystalline type of boron nitride, is thought for its robust thermal stability and electrical insulation properties. These properties make it excellent to be used in semiconductors to insulate parts, stop undesirable electrical currents, and improve gadget efficiency.
He emphasised that a-BN possesses excessive dielectric energy, a vital property for dependable digital efficiency, which signifies the fabric’s capability to resist excessive electrical fields with out degrading.
“The high dielectric strength demonstrated by a-BN is comparable to the best dielectrics available, and we don’t need water to make it. What we demonstrated in the paper was that including amorphous boron nitride yields improved device performance compared to conventional dielectrics alone,” said Robinson.
Robinson famous that though the coating improved the efficiency of the 2D transistor, making use of it to 2D supplies was difficult. Two-dimensional supplies lack dangling bonds—unpaired electrons on a fabric’s floor that work together or type bonds with different atoms—making the coating course of troublesome.
Utilizing a regular one-step course of at larger temperatures resulted in uneven and discontinuous coatings, far beneath the standard required for optimum digital efficiency.
To handle this, the crew developed a brand new two-step atomic layer deposition methodology. They first deposited a skinny low-temperature a-BN “seed layer” earlier than heating the chamber to typical deposition temperatures of 250 to 300 °C.
This methodology allowed the researchers to coat the 2D semiconductors evenly with a-BN and improved transistor efficiency by 30 % to 100 %, relying on the transistor design.
Robinson said, “When you sandwich 2D semiconductors between the amorphous boron nitride, even though it’s amorphous, you end up with a smoother electronic road, so to speak, that would enable improved electronics. The electrons can go faster through the 2D material than they could if they were between other dielectric materials.”
He additionally talked about that regardless of a-BN’s excessive dielectric energy, scientists are solely starting to discover its potential as a semiconductor gadget dielectric materials.
Robinson famous, “We have room for improvement even though it’s already outperforming other dielectric materials. The primary thing that we’re trying to do right now is improve the overall quality of the material and then integrate it into some complex structures you would see in future electronics.”
Cindy Chen, graduate pupil in supplies science and engineering; Riccardo Torsi, graduate analysis assistant in supplies science and engineering; Ke Wang, affiliate analysis professor within the Supplies Analysis Institute; Bangzhi Liu, affiliate analysis professor within the Supplies Analysis Institute. Different co-authors embody co-corresponding creator Yu-Chuan Lin, Nationwide Yang-Ming Chiao Tung College in Taiwan; Zhihong Chen and Joerg Appenzeller, Purdue College; Jessica Kachian, Intel Company; and Gilber B. Rayner Jr., The Kurt J. Lesker Firm are the opposite examine authors.
The Semiconductor Analysis Company funded this analysis via a program sponsored by the Nationwide Institute of Requirements and Know-how, the Middle for Emergent Practical Matter Science of Nationwide Yang-Ming Chiao Tung College, the Ministry of Training of Taiwan, and the US Nationwide Science Basis.
Journal Reference:
Chen, C. Y., et. al. (2024) Tailoring amorphous boron nitride for high-performance two-dimensional electronics. Nature Communications. doi.org/10.1038/s41467-024-48429-4
Supply:
Pennsylvania State College