Researchers from Northwestern University and the University of Virginia School of Engineering have created a new, polymer-based insulation for electrical circuits. This could allow more power to be placed in smaller spaces.
The rate at which progress is made in integrated circuits can be measured by either matching, exceeding, or falling behind the pace set by Gordon Moore, ex-CEO and co-founder of Intel. He predicted that the number of transistors per integrated circuit would increase by twofold every year. This prediction, now known as Moore’s Law, was made over 50 years ago.
It was believed that the pace of development had slowed in recent years. Controlling heat is one of the most significant challenges to putting more circuits on minor chips.
Patrick E. Hopkins, a University of Virginia professor with a courtesy visit in the Department of Materials Science, and Will Dichtel (a professor at Northwestern University’s Department of Chemistry) are part of a multidisciplinary team that is developing a new type of material that can keep chips cool while they shrink in size. This could help Moore’s Law to remain faithful. Their work was published in Nature Materials.
Low- k dielectrics are electrical insulation materials that reduce electrical crosstalk between chips. This material is the silent hero of electronics. It steers the current to avoid signal erosion and interference and can even pull the heat from the circuitry. As the chip becomes smaller, the heat problem increases exponentially because more transistors generate more heat. They are also closer together, making it more difficult for heat to evaporate.
Hopkins stated that scientists have been searching for a low- k dielectric substance to handle heat transfer and space problems at more minor scales. Hopkins said that although we have made great strides, breakthroughs will only be possible if a combination of disciplines exists. We used principles and research from many fields — mechanical engineering, chemistry materials science, and electrical engineering — in this project to solve a complicated problem that we could only solve.
Hopkins is a leader of UVA Engineering’s Multifunctional Materials Integration Initiative, which brings together multiple engineering disciplines to create materials with various functionalities.
“Seeing my problem’ through the lens of someone in a different field was fascinating, and it also led to ideas that eventually brought about advancement. Ashutosh Giri, an ex-UVA Engineering senior scientist, was a Ph.D. student in Hopkins’ lab and co-first author of Nature Materials. He is also a Rhode Island University mechanical, industrial, and systems engineering assistant professor.
Giri stated that the heart of the project was when Giri and the chemical team discovered the thermal functionality and understanding of their materials and when the mechanical- and materials groups understood the level of molecular engineering possible with chemistry.
Dichtel stated, “We are taking sheets of polymer that only have one atom thickness – this is what we call 2D – and controlling the properties by layering them in a specific architecture.” This collaboration was possible because of our efforts to improve the production methods for 2D polymer films.
Dichtel stated that the team is using this new material to meet the requirements for miniaturizing transistors on dense chips.
This material has tremendous potential to be used in the semiconductor industry, which is the industry that makes chips. He said that the material is either low in electrical conductivity or common k and has high heat transfer capabilities.”
The International Roadmap for Semiconductors recently identified this combination as a prerequisite for next-generation integrated circuits.
“For this project, we are focusing on the thermal properties of the new material class. This is amazing, but even more exciting is that we are just scratching to the surface,” Austin Evans, a Ph.D. student in Dichtel’s lab at Northwestern and the first co-author of the Nature Materials paper. The technological potential of developing new materials with unique properties is impressive.
“We are currently exploring new materials for chemical sensing. These materials can be used to sense and determine what chemicals and how many are in the air. This has wide-ranging implications. This knowledge can be used to optimize food storage, transport, and distribution, to reduce food waste. Evans stated that we will likely discover more unique characteristics in these new materials as we continue to explore.”