A transistor has to know how to stop. Billions of these tiny switches make a computer work, controlling the passage of electrical current. As engineers made them smaller, switching them off became increasingly difficult. Current leaked through, wasting energy. Tsu-Jae King Liu helped develop a solution that changed the shape of computing.
I first photographed her at Berkeley in November 2024, when she was dean of engineering. We walked down into the laboratories, through corridors that felt removed from the campus above. Machines hummed around us. The structures being made there were far too small to see, but Tsu-Jae explained them with a clarity that made their workings imaginable.
In a conventional flat transistor, a gate controls current flowing through a channel beneath it. As that channel becomes shorter, the gate struggles to maintain control. The FinFET raises the channel into a thin vertical fin, allowing the gate to control it from more than one side. That closer control reduces leakage and allows the switch to work at smaller dimensions.
Tsu-Jae helped develop the design with a team that included Berkeley colleagues Chenming Hu and Jeffrey Bokor. Her contribution included bringing the manufacturing steps together, turning a promising structure into something engineers could build. FinFETs became a foundation of modern processors, helping put powerful computing into devices small enough to carry in a pocket.
Listening to her, I enjoyed how readily she made this unfamiliar world understandable. She could explain the behavior of electrons, then the practical difficulties of making a device, without losing me along the way. Her patience was part of the pleasure of learning from her.
She joined Berkeley’s faculty in 1996 and became its first woman dean of engineering in 2018. In July 2025, she became the first woman to lead the National Academy of Engineering. I photographed her again at the National Academies in 2026.
What interested me during our Berkeley visit was how readily she moved beyond the transistor. We talked about what engineers choose to build and who benefits. She was concerned about people who might be overlooked as technology advances. When she spoke about students, that concern became more personal. She recognized different strengths and different ways of finding a place in the field.
Tsu-Jae has a gift for making the people around her feel valued. I have felt it in our conversations and in the notes she sends. Each is thoughtful and appreciative, written with a care that makes even a brief exchange feel personal. With all the demands on her time, she makes room for that attention.
I admire what she has helped make possible in computing. I am just as grateful for the kindness I have experienced in knowing her. She leaves you feeling that your time together mattered to her. Mine with her certainly has.
