In a significant advancement for the semiconductor industry, researchers from the School of Engineering at the Hong Kong University of Science and Technology (HKUST) have unveiled the world's first deep-ultraviolet (UVC) microLED display array designed specifically for the lithography machines integral to semiconductor manufacturing. This innovation addresses several limitations associated with traditional methods, suggesting a pathway towards more efficient and cost-effective manufacturing processes.
Supervised by Professor Kwok Hoi-Sing, the founding director of the State Key Laboratory of Advanced Displays and Optoelectronics Technologies at HKUST, the development has been a collaborative effort alongside the Southern University of Science and Technology and the Suzhou Institute of Nanotechnology of the Chinese Academy of Sciences. The team's work demonstrates that their UVC microLED can achieve high operational performance at various current densities, including for devices as small as 3 μm.
The research specifically focuses on improving maskless photolithography, which utilises short-wavelength ultraviolet light to create integrated circuit chips with diverse layouts. Traditional lithography approaches, prominent for their reliance on mercury lamps, present several downsides, such as substantial device size, limited resolution, increased energy consumption, and insufficient light efficiency. The new UVC microLED technology overcomes these challenges by offering a more compact device with optimal light output power density, thereby facilitating quicker exposure of photoresist films.
Mobile images generated during the study underscore the success of the prototype in effectively fabricating the first microLED device. By utilising maskless exposure techniques, researchers enhanced optical extraction efficiency and heat distribution, critical aspects that contribute to the overall performance and reliability of semiconductor devices.
Professor Kwok noted, "The team achieved key breakthroughs for the first microLED device including high power, high light efficiency, high-resolution pattern display, improved screen performance and fast exposure ability." He emphasized that the integration of the ultraviolet light source with the patterned mask allows for more efficient photoresist exposure, significantly reducing processing time.
Dr. Feng Feng, a postdoctoral research fellow at HKUST's Department of Electronic and Computer Engineering, added to this sentiment, outlining the advantages of their approach: "Compared with other representative works, our innovation features smaller device size, lower driving voltage, higher external quantum efficiency, higher optical power density, larger array size, and higher display resolution." This assertion positions their study as a leader in the field on multiple performance metrics.
The research paper, titled "High-Power AlGaN Deep-Ultraviolet Micro-Light-Emitting Diode Displays for Maskless Photolithography," has been published in the journal Nature Photonics and has garnered recognition within the industry, being listed as one of the top ten advances in China's third-generation semiconductor technology for 2024 by the 10th International Forum on Wide Bandgap Semiconductors (IFWS).
Looking ahead, the research team plans to build on their breakthroughs by further enhancing the performance characteristics of AlGaN deep ultraviolet microLEDs, refining their prototype, and developing high-resolution deep ultraviolet microLED display screens with resolutions ranging from 2k to 8k. The team comprises key members including Dr. Liu Yibo, Ph.D. graduate Dr. Zhang Ke, and collaborating researchers from partner institutions.
Source: Noah Wire Services