DNA scaffolds for 3D electronics; removing defects from MoS2.
Researchers from Columbia University, Brookhaven National Laboratory, and University of Minnesota used DNA to help create self-assembled 3D electronic devices with nanometer-size features.
The team deposited arrays of gold squares on a surface, onto which they could attach short pieces of DNA. These served as anchors to which they could fasten eight-sided diamond-like octahedral DNA frames that self-assemble into 3D frameworks at specific surface locations. The DNA scaffolds were then coated with silicon oxide, laced with tin oxide, and connected to electrodes to create light sensors that responded electrically when illuminated.
“These gold arrays with anchored DNA strands promote the growth of 3D DNA scaffolds on designated areas in desired patterns and orientations, which allows us to establish and integrate this DNA onto an electronic wafer,” said Oleg Gang, professor of chemical engineering and of applied physics and materials science at Columbia Engineering and leader of the Center for Functional Nanomaterials’ Soft and Bio Nanomaterials Group at Brookhaven National Laboratory, in a statement. “We’ve demonstrated that not only can we create 3D structures from DNA, but integrate them into microchips as part of the workflow of how electronic devices are fabricated. We can place thousands of these structures at specific sites on silicon wafers in a scalable way. This demonstrates that we can drastically change how we fabricate complex 3D electronic devices.”
The team plans to use the method to create more complex electronic devices using more than one material. [1]
Researchers from Ulsan National Institute of Science and Technology (UNIST) and Pohang University of Science and Technology (POSTECH) found a way to remove defects in molybdenum disulfide (MoS2).
“The research team utilized pentafluorobenzenethiol (PFBT) at 200°C to repair defects in MoS2, achieving a recovery of the atomic ratio of molybdenum to sulfur (Mo:S) to a near-ideal 1:1.98. Typically, during the deposition process, sulfur vacancies (SVs) create defects that lead to an actual ratio of approximately 1:1.68, which hinders electron flow and affects the performance and durability of the semiconductor. Therefore, repairing these defects is essential for restoring the material to its theoretical atomic ratio,” explained UNIST’s JooHyeon Heo in a press release.
“The major advantage of our technique is its compatibility with existing silicon semiconductor back-end-of-line (BEOL) processes, as it can occur at temperatures below 200°C,” added Haksoon Jung of UNIST. “The BEOL process connects previously deposited components on a substrate and must be conducted below 350°C to prevent damage to the devices.”
Transistor devices made with the repaired MoS2 showed a 2.5-fold improvement in charge mobility compared to devices with defects. Additionally, the subthreshold swing value was reduced by approximately 40%. [2]
[1] Michelson, A., Shani, L., Kahn, J.S., et al. Scalable fabrication of Chip-integrated 3D-nanostructured electronic devices via DNA-programmable assembly. Sci. Adv. 11, eadt5620 (2025). https://doi.org/10.1126/sciadv.adt5620
[2] Jung, H., Kim, M, Lee, Y., et al. Back-End-of-Line-Compatible Passivation of Sulfur Vacancies in MoS2 Transistors Using Electron-Withdrawing Benzenethiol, ACS Nano (2025). https://dx.doi.org/10.1021/acsnano.4c12927
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