ALD for Ru wiring; vertical nanolasers; hydrogel semiconductors.
Researchers from Ulsan National Institute of Science and Technology (UNIST), Hongik University, and Tanaka Precious Metal Technologies developed an atomic layer deposition (ALD) process for creating chip interconnects using a ruthenium (Ru) precursor with a thermal stability up to 400 °C. The high-temperature ALD process can produce dense, high-quality Ru films without degradation.
Films grown using the precursor had resistivity values as low as 10.6 μΩ·cm. The process showed a growth rate of approximately 1.28 Å per cycle, requiring only about 8 cycles to form a coating with over 95% conformality, enabling it to effectively cover complex 3D structures such as narrow trenches. Additionally, the process demonstrated good substrate selectivity, depositing ruthenium only on targeted areas and avoiding nucleation on SiO₂.
“Achieving low-resistance wiring with high uniformity and process efficiency at nanoscale dimensions is crucial,” said Soo-Hyun Kim, a professor in the Department of Materials Science and Engineering at UNIST, in a statement. “Our development offers a significant step toward more reliable and high-performance chip manufacturing.” [1]
Researchers from Korea Advanced Institute of Science and Technology (KAIST), Pohang University of Science and Technology (POSTECH), Hong Kong Polytechnic University, University of Hong Kong, City University of Hong Kong, and Nankai University developed a 3D printing method that can create vertical nanolasers for ultra-high-density optical integrated circuits by stacking perovskites.
The method, called ultra-fine electrohydrodynamic 3D printing, uses electrical voltage to precisely control ink droplets at the attoliter scale, enabling printing of pillar-shaped nanostructures directly and vertically at desired locations without requiring subtractive processes.
“This technology allows for the direct, high-density implementation of optical computing semiconductors on a chip without complex processing. It will accelerate the commercialization of ultra-high-speed optical computing and next-generation security technologies,” said Ji Tae Kim, a professor in the Department of Mechanical Engineering at KAIST, in a press release.
The resulting printed perovskite nanostructures are extremely smooth, improving laser efficiency. In addition, the color of the emitted laser light could be precisely tuned by adjusting the height of the nanostructures, a trait the researchers used to create laser security patterns that could be part of anti-counterfeiting technology. [2]
Researchers from the University of Hong Kong, University of Cambridge, and University of Chicago designed hydrogel-based 3D transistors that can mimic both the behavior and structure of neurons in the human brain.
Synthesized in water through a 3D self-assembling process, the hydrogel semiconductors are soft and biocompatible, possessing tissue-like properties that make them capable of hosting living cells.
“This is just the beginning of a new era of bioelectronics. With further optimization, such Jelly-like 3D biochips could revolutionize healthcare, education, and even daily life,” said Shiming Zhang, assistant professor of Wearable Bioelectronics at HKU’s Department of Electrical and Electronic Engineering, in a statement. “We look forward to the launch of regulatory frameworks to guide the development of such groundbreaking technologies for medical uses.” [3]
[1] H. Nakatsubo, D. Mohapatra, E.-S. Lee, et al. Small and Simple Molecular Structure Based Thermally Stable Ruthenium Precursor in Advancing Ruthenium ALD Process for Scaled Interconnect Metallization. Adv. Sci. (2025): e19209. https://doi.org/10.1002/advs.202519209
[2] S. Hu, T. Wang, Z. Zhou, et al. Nanoprinting with Crystal Engineering for Perovskite Lasers. ACS Nano 2025 19 (50), 42648-42657 https://doi.org/10.1021/acsnano.5c16906
[3] D. Liu, J. Bai, X. Tian, et al. Increasing the dimensionality of transistors with hydrogels. Science 390, 824-830 (2025). https://doi.org/10.1126/science.adx4514
 |
 |
 |
 |
 |  |
 |  |
 |
Leave a Reply