Engineers at The University of Texas at Austin are spearheading a groundbreaking initiative that could transform the production of semiconductor chips. By collaborating with both academic and industry leaders, they have developed a novel 3D printing method known as Holographic Metasurface Nano-Lithography (HMNL). This innovative approach promises to enhance the speed, efficiency, and environmental sustainability of advanced electronics manufacturing.
The HMNL technique holds vast potential, with applications spanning from smartphones to robotics and aerospace. It enables the creation of previously unattainable designs, such as 3D printed capacitors and electronic packages that can fit into unconventional spaces. This advancement could allow for embedding artificial intelligence in customized configurations tailored to the specific needs of robots or rockets.
Breaking Down Holographic Metasurface Nano-Lithography
In an exclusive interview, Michael Cullinan, Associate Professor at the Cockrell School of Engineering’s Walker Department of Mechanical Engineering, shared insights into the challenges and workings of HMNL. According to Cullinan, the most significant technical hurdle was integrating a new materials resin chemistry with a novel optics design and exposure method.
“We want to make something that is the size of a penny in about one minute that has 500nm features in it, and it needs to contain both insulators and conductors simultaneously patterned at that throughput and resolution,” Cullinan explained.
The HMNL process utilizes sub-wavelength-patterned metasurface masks to create multi-colored holograms in a photocurable metal-polymer hybrid resin. This allows for the simultaneous patterning of entire 3D, multi-material nanostructures using a single light exposure. The hybrid resin is designed to use ultraviolet (UV) light to pattern the silver conductor and visible light to pattern the polymer dielectric, enabling the fabrication of both materials at once.
Technical Innovations and Advantages
The use of metasurface optics in HMNL overcomes many limitations of traditional holographic 3D printing, such as low resolution and small patterning areas. Metasurfaces can be encoded with higher information density than conventional spatial light modulators, allowing for the fabrication of structures with approximately 500 nm resolution over large areas.
Preliminary volumetric patterning using HMNL demonstrates a build rate of over 20 mm3/s, significantly faster than conventional multi-step semiconductor packaging fabrication approaches.
Furthermore, metasurface optics can be engineered to produce various holographic patterns when exposed to different light colors, facilitating the creation of multi-material structures with features as small as 36 nm.
Future Prospects and Commercialization
The team is currently focused on transitioning the lab-scale HMNL system to a tool suitable for cleanroom environments in semiconductor packaging facilities. This involves reconfiguring the optical layout for direct wafer printing and adding alignment optics to ensure precise feature placement.
“The goal is to have a prototype of this commercial scale HMNL system operating in the R&D fab at the Texas Institute for Electronics by the end of 2026,” Cullinan stated.
The collaboration with the Texas Institute of Electronics and support from programs like DARPA NGMM and AMME are crucial for this transition. The team aims to gather yield and reliability data essential for commercial viability.
Implications for the Semiconductor Industry
The development of HMNL could have far-reaching implications for the semiconductor industry. By enabling faster and more efficient production methods, this technology could reduce costs and environmental impact, addressing some of the industry’s most pressing challenges.
As the demand for advanced electronics continues to grow, innovations like HMNL are poised to play a critical role in meeting these needs. The successful commercialization of this technology could mark a significant milestone in semiconductor manufacturing, paving the way for more sustainable and versatile electronic devices.
As the project progresses, the industry will be watching closely to see how HMNL can be integrated into existing manufacturing processes and what new possibilities it might unlock for future technologies.
