Vitals
Current affiliation: Arkema
Age: 39
PhD alma mater: Michigan State University
If I were an element, I’d be: “Fluorine. It’s highly reactive, full of energy, and capable of transforming whatever it bonds with. It can be unpredictable but keeps things interesting.”
My alternate-universe career is: “An architect, because I love designing and building things; an archeaologist, traveling the world and uncovering stories from human history; or a geologist, since I’ve always been drawn to minerals, rocks, and the way their compositions create such beautiful colors.”
Shortly after Behnaz Ghaffari started designing sustainable fluorochemicals for the French firm Arkema, she traveled to Calvert City, Kentucky, to work on a project. As part of the visit, she toured the firm’s commercial plant, which made fluorine-based polymers, refrigerants, and semiconductor gases. Even though Ghaffari was an R&D chemist, she peppered the plant operator with questions about the manufacturing process.
“We went there with a particular purpose, but . . . she was really curious about everything that was happening,” says Jessica DeMott, a senior R&D manager at Arkema who toured the plant with Ghaffari.
Ghaffari has been asking questions throughout her life. Growing up in Shiraz, Iran, her favorite book was The Big Book of Tell Me Why, a children’s book that addresses such heady mysteries as How big is the universe? and What keeps the sun shining?
Her curiosity would eventually take her all over the world, from Michigan for her PhD to Switzerland and Canada for postdoctoral positions. “I was intentional about picking something new every time I moved,” Ghaffari says. “I wanted to pick up different science, different chemistry.”
During her postdoctoral research at the University of Ottawa, Ghaffari joined a lab that was working with Arkema to design fluorochemicals that would be more sustainable than existing options, such as planet-warming hydrofluorocarbons and perfluorinated compounds (PFCs), and hazardous per- and polyfluoroalkyl substances. She enjoyed the challenge of creating new materials and continued working with the company afterward.
Ghaffari employs several methods to invent new chemicals. Sometimes she starts with an existing fluorochemical and tweaks it to improve the sustainability characteristics. In other cases, she combines two molecules to make something new. Using synthetic chemistry, she can arrange atoms and bonds to reduce a molecule’s lifetime in the atmosphere—and its impact on global warming.
Ghaffari says that she’s “thinking about the environmental impact of the materials during the design of the molecule, from the very start.”
Demand for sustainable fluorochemicals is rising. They’re needed for fluids that cool data centers and gases to etch high-performance computer chips, applications that are expanding rapidly because of the growth of artificial intelligence.
Semiconductor manufacturers use PFCs to carve ultraprecise designs on microchips. During etching, the compounds are heated to form a plasma, thus releasing reactive fluorine radicals. Fluorine bombards the chips—coated with a protective stencil that defines the pattern—and peels away the exposed silicon.
PFCs are stable and unreactive until they are exposed to the high levels of energy needed to form a plasma, which makes them robust for industrial processes. But their longevity and penchant to trap heat also make them potent greenhouse gases.
During the manufacturing process, some PFCs leak into the atmosphere, and they represent the biggest portion of the semiconductor industry’s direct manufacturing emissions. In 2021, PFCs used for chip manufacturing contributed more to global warming than 3 million cars driven for a year, according to a report from the trade organization Semi (PDF).
Ghaffari says firms are eager for molecules that achieve the same performance as existing PFCs without harming the environment. But so far there aren’t many options to replace critical etching gases, particularly carbon tetrafluoride, which is used to etch the most-advanced microchips.
In addition to reducing the global warming potential of fluorine gases, Ghaffari is working to reduce the energy needed to make them. Last year she started on a project to increase the purity of a molecule used for refrigerants to a level that would be suitable for semiconductor manufacturing. But achieving near-perfect purity requires massive amounts of energy.
Drawing on her experience in Calvert City, Ghaffari was able to redesign the manufacturing process to significantly reduce energy consumption, an innovation that earned her a sustainability award from Arkema. “When you’re on an industrial platform, every single step matters for the sustainability profile,” she says. “You’re looking at every step and the carbon footprint of each step.”
As the AI boom continues, the chips and data centers that power the technology will need to grow. The stubbornly persistent emissions from that growth threaten to warm the planet for centuries. But Ghaffari hopes the materials she’s designing will rein in AI’s climate impacts and ensure that this expansion is more sustainable.
