ASU experts share insights about this microscopic world

The field of microelectronics plays a macro-sized role in our lives. It's responsible for the tiny brains—microchips—that power most electronic devices: familiar technology like smartphones and TVs, important medical equipment from hearing aids to MRI scanners, and even everyday appliances like microwave ovens and thermostats.

Our dependence on microchips is now underscored by the shortage that has recently stalled the production of cars and cell phones. For supply and security reasons, there's growing interest in making more semiconductors and microchips in the U.S.

With its cutting-edge facilities, strategic partnerships, educational programming and research capabilities, Arizona State University is positioning Arizona as the ideal hub for this growing industry.

What's the difference between semiconductors, microchips, and microelectronics?

Basically, semiconductors are used to make microchips; microchips are physical devices you can hold in the palm of your hand; and microelectronics refers to the field or industry as a whole.

Semiconductors are a type of material with the traits of both conductors, like aluminum, and insulators, like glass. Semiconductors such as silicon have enabled us to make electronic devices smaller, faster and more reliable.

They usually come to fabrication plants as thin, flat wafers—similar to dinner plates.

"When you have lots of different layers of semiconductors in various structures, you get devices like transistors, and devices wired together become microchips," says Zachary Holman, an associate professor in ASU's Ira A. Fulton Schools of Engineering.

Nowadays, people often use the term "semiconductors" as a shorthand for chips and other devices made with semiconductor materials.

How small are microelectronic devices?

The "micro" stands for micrometer, which is one-millionth of a meter. (An average human hair is around 60 micrometers thick.) Microchips themselves aren't that tiny, but if you stuck one under a microscope, it would have features and regions at that micrometer scale. Today, some chips even have features on the nanometer scale. A nanometer is one-billionth of a meter.

In 2021, the tech industry hailed the improved capacity of a supercomputing chip the size of an iPad, along with the creation of the world's smallest single-chip system the size of a dust mite. Despite this dramatic size difference, both are microelectronic devices because both have micrometer-scale features.

The microchips found in everyday computers and smartphones range from the size of a fingernail to a postage stamp.

How are microchips made?

The manufacturing process has become much more sophisticated since the first microchip made its debut in 1959. It starts with design—engineers use a software program to lay out the microchip's structure, like an architect creating the blueprint of a house.

The design goes to a fabrication plant—often called a "fab" for short, or sometimes a foundry—which takes a base semiconductor wafer and layers different materials like metals, oxides and other semiconductors on top of it.

"They also do patterning steps, which are similar to the old camera film exposure processes. After depositing a layer, the wafer goes into a chemical bath or a gaseous environment that removes material from select areas, while other areas are protected," Holman says. "That process gets repeated up to hundreds of times to form all of the elements for that chip's design."

These patterning steps etch the layered wafer to match the initial design.

There are many chips per wafer, so once all its layers are complete, the fab "dices" it, separating out the individual chips like slices of a sheet cake. The final step is to package the chips by bonding them to circuit boards, those green plastic panels you find inside electronics. The fab ships the final creations to other manufacturers, who use them to make products such as cars, TVs and cell phones.

Why has there been a microchip shortage? Are more fabs the solution?

Manufacturers from tech, auto and other industries expected that their sales would go down during the COVID-19 pandemic, so they ordered fewer chips from fabs. However, pandemic optimism and vaccine availability from the summer of 2021 led to more consumer spending. Manufacturers suddenly had more demand than supply for microchip products.

Now, fabs are being flooded with additional requests as many industries try to order more chips at once.

"It's hard to increase the supply rapidly because the chip fabrication process takes months," Holman says. "The fabs themselves are really complex and expensive. From the start of construction to a fab being operational is typically three-plus years."

Currently, most semiconductor and chip manufacturing happens overseas, with the U.S. accounting for just 12% of manufacturing globally, according to the Semiconductor Industry Association's 2020 report.

Building additional fabs in the U.S. would help relieve similar global chip shortages in the future by adding to the world's overall fabrication capability. If U.S. fabs prioritize orders from U.S. consumers, that could also help protect our domestic supply chain.

What are the national security issues to consider with microelectronics?

"Think of the U.S. Department of Defense's computer systems, communications systems, transportation systems—they all rely on microelectronic devices to function properly," says Nadya Bliss, executive director of ASU's Global Security Initiative.

These devices are integral not only to military operations, but also critical sectors like health care and the economy. If any of those were compromised, Bliss says, the consequences would also impact national security.

In a recent report, the National Security Commission on Artificial Intelligence noted the need to develop a resilient microchip and semiconductor supply chain in the U.S. in order to stay ahead in the geopolitical technology arena.

"Increasing the design and fabrication of these technologies in the U.S. would address a major national security vulnerability—that an adversarial nation could tamper with the technology at some point in the supply chain," Bliss says.

How is ASU helping Arizona lead the U.S. microelectronics industry?

An educated workforce is key for Arizona to become a home for microelectronics manufacturing. While ASU has been producing top-notch engineering graduates for 65 years, the Ira A. Fulton Schools of Engineering is now investing in a talent pipeline specifically for microelectronics with the creation of its new School of Manufacturing Systems and Networks.

"With the new fabrication facilities coming into the Valley from Intel and Taiwan Semiconductor Manufacturing Co., we're expecting over 10,000 new jobs," says Kevin Reinhart, director of research project management at ASU's Knowledge Enterprise.

These companies and many others can take advantage of ASU's research expertise and specialized equipment at ASU sites like the Advanced Electronics and Photonics facility, the ASU NanoFab and the Eyring Materials Center. Each enables development of new materials, methods and designs for microelectronics at industry scale.

"At ASU's MacroTechnology Works site, we've got 50,000 square feet of cleanroom facilities," Reinhart says. "From a university perspective, we're very unique in that aspect."

These facilities also provide opportunities for ASU students to gain the critical hands-on experience that employers want.

In addition, ASU is applying funds from Arizona's New Economy Initiative to create five Science and Technology Centers (STCs), two of which will contribute directly to the state's microelectronics industry—the Advanced Materials, Processes and Energy Devices (AMPED) STC and the Manufacturing, Automation and Data Engineering (MADE) STC.

Fabrication plants use tons of water, so why are we building them in the desert?

Water is a crucial part of the chip manufacturing process. Between adding each delicate layer of the wafer, the fab must wash away all residue so that no bacteria or particles obstruct the chips' microscopic pathways.

But to rinse off every speck of debris, the water itself must be extra clean—no minerals, no organic material. Fabs create what's called ultra-pure water for this purpose, and it's so clean that it's actually not safe for humans to drink.

Creating ultra-pure water and washing wafers produces lots of leftover wastewater. So why bring more fabs to Arizona's water-scarce desert?

"The important question is not, 'Do we have enough water?' but, 'How do we invest our limited water?'" says Dave White, director of ASU's Global Institute of Sustainability and Innovation and professor in the School of Community Resources and Development. "We need to look for the most efficient water uses that have the greatest social, economic, environmental returns. I would call semiconductor manufacturing in our region a water-smart industry."

Manufacturing brings many benefits to the state, including skilled, high-wage jobs and a supply of high-demand products. But the state benefits the fabrication plants as well: Arizona has a highly educated workforce and a low risk of environmental hazards such as earthquakes or hurricanes.

Fabs in Arizona need to be innovative and efficient with their water use and reuse, but that's just as true for cotton fields and homes, White says.

Intel's partnership with the city of Chandler is a prime example of how fabs can accomplish this. There, they take wastewater from Intel's fabs and pump it back into the ground. As it filters through the earth, the water purifies naturally, and it also recharges the aquifer. Groundwater levels are concerningly low throughout the state, so the Intel-Chandler partnership is a solution for two pressing issues at once.

What's next for microelectronics?

Talk about the future of microchips, and you're sure to run into Moore's law. It's more of an idea than a proven scientific theory. Essentially, it says that microchips' computational power doubles (and their size halves) about every two years. But it implies that microchips will hit a limit from which they can't be improved anymore.

Holman compares Moore's law to a scene from the movie "Spinal Tap" where a rock musician shows off his amplifier that goes up to 11, instead of the usual 10.

"Moore's law has been about one knob of optimization, namely making things smaller in two dimensions, and that knob has already been turned up to 11. That's why, going forward, the technical innovation in microelectronics is about building in three dimensions," he says.

Putting different capabilities that normally exist on separate chips—such as sound, display, computation and memory—together to create an all-in-one chip is another new direction for microelectronic technology, he adds.

Additionally, microelectronics will be crucial in the shift to renewable energy. According to the U.S. Energy Information Administration, only 12.6% of our national energy consumption came from renewable sources in 2020.

"How do we get closer to a hundred percent? Well, you need to have a lot more control over where electricity is being generated, where it's being consumed and stored, and when," Holman says.

Electronics that can share information and distribute power across the grid will allow us to draw from many renewable sources and know how much is available from a source at any given time.

With around 300 days of solar-charging sunshine every year, coupled with its microelectronics research, development and fabrication capabilities, Arizona is an ideal place to find the technological solutions we need for a future that is both sustainable and leading-edge.

Provided by Arizona State University