Pursuing a Rich Portfolio of Microelectronics Research

 

Researchers are finding solutions in every dimension of the microelectronics domain.

Microelectronics is a technology space concerned with very small things, but it’s a very big deal, as everyone learned when the world’s supply of semiconductor chips ran short in 2020. When the COVID-19 pandemic drove up demand for computers while simultaneously disrupting the supply chains that produce them, it was a wake-up call. Suddenly, it was obvious how important and pervasive these technologies are—and how much their availability had been taken for granted. 

Grainger Engineering’s microelectronics work encompasses a range of education and workforce development efforts in addition to research. 

Further, although the U.S. accounts for about half of the ~$500 billion global semiconductor market in sales, only about 12% of the semiconductor chips sold are manufactured in the U.S. That’s down from 37% in 1990. Experts have raised concerns about the national security implications of using chips manufactured overseas. Can we confidently put such chips in a missile, for example? One response has been the $280 billion CHIPS and Science Act of 2022, whose top priority is to increase U.S. domestic research on, and manufacturing of, semiconductors. 

It’s a challenging time, and Grainger Engineering researchers are rising to that challenge: they’re making contributions across every level of the microelectronics stack, in areas ranging from materials discovery to chip design to manufacturing and beyond. In doing so, they are building upon the illustrious legacy of pioneers such as John Bardeen of Electrical & Computer Engineering (ECE) and Physics, who was awarded the Nobel Prize in 1956 for the invention of the semiconductor transistor, and Jack S. Kilby, an Electrical Engineering alumnus who received the Nobel Prize in 2000 for the invention of the integrated circuit. 

While dozens of faculty from multiple departments are involved, Grainger Engineering’s three interdisciplinary research units (IRUs) are arguably UIUC’s primary hotbeds of microelectronics work. 

For example, in the Materials Research Lab (MRL), teams are pursuing new materials for quantum and conventional microelectronic devices, physical characterization of microelectronics, and other relevant topics in quantum science. In the Holonyak Micro & Nanotechnology Lab (HMNTL), the focus is on devices, including heterogeneous integration of photonics, electronics, and various materials, as well as complicated designs for VLSI and conventional silicon CMOS chips. Finally, the Coordinated Science Lab (CSL) is strong in microelectronics systems design, notably in areas such as edge computing, AI, and specialized chips for high-intensity computation. 

Launching New Centers

One of Grainger Engineering’s newest microelectronics initiatives is HMNTL’s Center for Advanced Semiconductor Chips with Accelerated Performance (ASAP), an NSF Industry-University Cooperative Research Center (IUCRC) helmed by Shaloo Rakheja, an assistant professor in ECE and HMNTL. Its mission is to develop solutions that alleviate interconnect challenges and improve the energy efficiency of next-generation information-processing systems. 

“One of the biggest problems with microelectronics today is its energy efficiency,” explains Rakheja. “We are consuming a lot of energy, and that’s obviously increasing our carbon footprint.” 

The biggest culprit is in the transfer of data during computation: a complex fingernail-sized microprocessor might contain dozens of miles of copper interconnects through which data are moved. Data needed for AI applications must be continually transferred between a memory (DRAM) chip and the CPU. Indeed, more than half of the energy consumption of microelectronics is due to interconnects, both on- and off-chip, and not due to the actual computation; the proportion is even worse when data-intensive tasks, like image recognition, are being performed. 

Rakheja says that the overarching goal of ASAP is “to develop new fundamental technology solutions going all the way from advanced materials, through advanced devices and circuits, to advanced architectures, that are put together holistically to allow us to reduce the energy consumption by a factor of a hundred.” 

ASAP isn’t the only NSF IUCRC tackling microelectronics questions at UIUC. CSL’s Center for Advanced Electronics through Machine Learning (CAEML) was founded in 2017, and recently received funding for a second five-year phase. Directed by Elyse Rosenbaum, who is the Melvin and Anne Louise Hassebrock Professor in ECE, CAEML applies machine learning to the design of optimized microelectronic circuits and systems, thereby increasing the efficiency of electronic design automation (EDA) and resulting in reduced design cycle time and radically improved reliability. 

A newly announced major center in this domain is the $40 million Center for Evolvable Computing (ACE), directed by Josep Torrellas, the Saburo Muroga Professor of Computer Science. 

It’s one of seven centers nationwide that just won funding under the Joint University Microelectronics Program 2.0 (JUMP 2.0) program, which was established by the Semiconductor Research Corporation (SRC) and DARPA to support work across seven research themes of critical importance to the semiconductor sector. 

ACE, which is a 13-university consortium led by UIUC, will work to develop an “evolvable computing” distributed framework designed for extensibility and composability, with the ultimate goal of delivering a dramatic reduction in the energy consumption of distributed computing. 

Another three of the seven new JUMP 2.0 centers also have UIUC leadership. The PRocessing with Intelligent Storage and Memory (PRISM) Center is being co-directed by Nam Sung Kim, the W.J. “Jerry” Sanders III – Advanced Micro Devices, Inc. Endowed Chair in ECE. It will pave the way towards providing the massive distributed memory and storage needed for future applications. Naresh Shanbhag, the Jack S. Kilby Professor of ECE, is on the leadership teams of both the Center for the Co-design of Cognitive Systems (CoCoSys) and the Center for Ubiquitous Connectivity (CUbiC). CoCoSys will design energy-efficient cognitive and artificial intelligence systems, while CUbiC will focus on energy-efficient, high-data-rate wireline and wireless connectivity to enable emerging data-centric applications. 

“Our participation in both CUbiC and CoCoSys creates a unique opportunity to discover holistic solutions to the energy efficiency problem in computing by exploring energy-efficient ways of transferring data jointly with novel ways of processing that data, e.g., by employing brain-inspired models of computation,” says Shanbhag. 

Small Projects Making Big Contributions 

In addition to such center-scale efforts, a myriad of smaller-scale UIUC projects are making important progress in the microelectronics space. 

For example, ECE professor Rakesh Kumar recently attracted attention for the development of FlexiCores, the world’s first commercially viable flexible plastic microprocessor chips. They can be manufactured at scale for less than a penny each, and are based on bendable thin-film transistors, opening the door to future applications such as smart bandages that can detect a healing wound’s status, or smart food packaging that can track progress along a supply chain. 

Another example is a solution recently developed in the group of David Ruzic, who is an Abel Bliss Professor in Nuclear, Plasma & Radiological Engineering. His team found a way to streamline microchip production by using annular surface wave plasma (SWP) antennas to prevent buildup of tin in a key component of the manufacturing equipment. They thus eliminated the need to remove and clean that component periodically, a process that slowed production and added costs. 

Yet another recent breakthrough shed light on poorly understood resistor aging effects and their impact on the frequency drift of RC oscillators—a clock source that would be preferable for many applications but is highly susceptible to performance degradation over time. 

Techniques were then developed to compensate for the aging effects. This work from the group of Pavan Kumar Hanumolu, the Seendripu Family Professor in ECE, will expand the possibilities for commercial deployment of RC oscillators. 

Educating the Workforce 

Notably, Grainger Engineering’s microelectronics work encompasses a range of education and workforce development efforts in addition to research. 

For example, the ASAP IUCRC is committed to providing students with intensive cross-disciplinary learning opportunities to enable effective research in this complex field. “Today, in order for us to understand how we can deliver functionality... it’s very critical to understand different steps of the design, because it’s very important to communicate,” says Rakheja. “A materials scientist should be able to communicate with a circuit designer. Likewise, a circuit designer should understand, this is the new material that we’re working with.” 

Similarly, CAEML has been offering a robust set of student and workforce development opportunities since its inception, ranging from semiannual student workshops, to webinars in which students present their work to industry partners, to active industry mentoring of students, among other efforts. CAEML faculty have presented seminars and tutorials to industry audiences, attracting new industry partners while informing practitioners about the state-of-the-art use of machine learning for design. It’s evidence of CAEML’s success that to date, 15 graduated CAEML students have been hired by CAEML industry partners. 

Collectively, Grainger Engineering’s microelectronics efforts offer enormous depth and breadth. Together, they are finding ways to produce more, and better, microelectronics devices to meet urgent societal needs in the U.S. and around the world. 

Researchers in The Grainger College of Engineering are leading the way in microelectronics through a variety of multi-million-dollar centers

 

ACE Center for Evolvable Computing Joseph Torrellas (Computer Science) is heading up the $40M ACE 

Josep Torrellas (Computer Science) is heading up the $40M ACE Center, part of the Joint University Microelectronics Program (JUMP) 2.0 to develop new computing paradigms that will be critical to achieving national technological goals in microelectronics. This partnership is funded by the Semiconductor Research Corporation, in cooperation with DARPA.

Center for Advanced Electronics through
Machine Learning (CAEML) 

Elyse Rosenbaum (Electrical and Computer Engineering) leads the center in its 6th year of operation as a NSF-supported Industry-University Cooperative Research Center (IUCRC), CAEML focuses on applying machine learning to optimized microelectronic circuits and systems.

Center for Advanced Semiconductor Chips with Accelerated Performance (ASAP) 

ECE Professor Shaloo Rakheja is heading ASAP, an NSF IUCRC focused on designing energy-efficient chips that will lead to a more powerful information infrastructure. This center officially launched in 2023.

Devices 

Dozens of other researchers across the college work on microelectronics, including Minjoo Larry Lee and John Dallesasse, who are working on projects focused on integrated photonics. Milton Feng researches ultra-high-speed devices for communication, and Wenjuan Zhu created atomically thin transistors and memories. All are ECE faculty.

Hybrid-Magnon Quantum Devices 

Axel Hoffmann (Materials Science) is running a $4.2M Department Of Energy effort entitled “Hybrid- Magnon Quantum Devices” that is focusing on how magnetic materials could improve the performance of quantum computing circuits. Hoffmann works with four other UIUC professors and two others at Argonne National Laboratory on this project.

Hybrid Quantum Architectures and Networks (HQAN) 

Brian DeMarco (Physics) leads the $25M HQAN, one of five NSF Quantum Leap Challenge Institutes (QLCI). The multi-university center is working with14 private sector companies and government lab collaborators to examine strengths of different quantum systems.

Quantum Sensing and Quantum Materials 

A DOE Center on Quantum Sensing and Quantum Materials, led by Peter Abbamonte (Physics), is focused on inventing several new quantum sensing techniques for studying elementary phenomena in quantum materials, which could establish the groundwork of future advancements in microelectronics.