Rose Castanares ('88, B.S., Ceramic Engineering) never imagined she'd return to The Grainger College of Engineering at the University of Illinois Urbana-Champaign as a leader overseeing a transformation in one of the most critical global industries. During her undergraduate journey through the Department of Materials Science and Engineering, she encountered some personal academic struggles but learned critical lessons about communication and collaboration outside the classroom — experiences that combined to power her career ascension. 

Today, Castanares is president of Taiwan Semiconductor Manufacturing Company (TSMC) Arizona, where she oversees the construction and operation of advanced semiconductor facilities that will produce the world's most sophisticated semiconductor chips on American soil. Her role places her at the center of a critical national security and economic initiative, managing everything from cutting-edge manufacturing processes to a rapidly growing workforce of thousands. TSMC Arizona is rapidly expanding under her leadership, as funding reaching $165 billion — the largest foreign direct investment in U.S. history — has been earmarked to further build facilities in the state. 

During her Sept. 12, 2025 visit to campus, Castanares spoke with students in an evening Fireside Chat event, featuring Materials Science and Engineering Department Head Nancy Sottos as panel emcee. Grainger Engineering Dean Rashid Bashir and Materials Science and Engineering Associate Professor Qing Cao sat down with Castanares for an in-depth conversation.

The discussion shared insights from Castanares’ remarkable career trajectory and offered practical advice to current students navigating an increasingly complex technological landscape. Her perspective bridged the gap between academic preparation and industry reality, drawing on extensive experience in the semiconductor sector and her unique position leading one of the most ambitious manufacturing projects in modern history.

You're an alumna of the University of Illinois Urbana-Champaign and now a leader in TSMC's historic United States expansion. Can you tell us about your journey?

Castanares: I’m honored to be here. I haven't been back since 1990 or so, and it's just been fantastic to see the growth and development here. It brings back a lot of memories, and I’m very proud to have come from Illinois, from the University of Illinois Urbana-Champaign. The memories here have been just fantastic and I’m just really honored to be back.

I couldn’t have imagined being here a year and a half ago. Like I told some of the students at lunch, I was not the best student. When I came here, coming from a small school in the suburbs and from a very strict family, coming to Illinois, and you've got the world at your feet in terms of having so many activities with so many people, I really struggled with coursework. (It was hard even though) I was salutatorian at my high school.  

But I learned other things that were really important in my career. I learned how to communicate, how to connect with people and how to network. I joined a sorority. I was a bookworm in high school; that was kind of like a challenge to myself, right? If I can get into a sorority, that means that I can actually talk to people.

So all those things kind of contributed to my career, because I wasn't the best engineer. I probably wasn't the best manager, but I was kind of in-between. I was able to talk to people in a way that was technical, that was simple enough for people to understand. I could connect with people, and particularly customers felt that I was trying to help them, and I think I showed up and persevered. My management felt they wanted to be able to make use of my background in places where I never thought I would have been able to go. I was in sales and, of course, all of our salespeople have engineering degrees, but there's a difference between an engineer doing sales and an engineer doing fab work.

I would never have thought that I'd be able to go to TSMC Arizona as president. That was just not even in my wildest dreams. I was lucky enough and blessed enough to have people that believed in me, that put me in that position and who supported me — including my family, who managed to help me and support me throughout that whole journey.

Can you give us a sense of the scope of the TSMC Arizona project and what it means for the semiconductor landscape?  

Castanares: In 2019 or so, our largest customer came to TSMC, and this was when I was working in California, and the vice president in charge of this particular customer. This customer said, ‘TSMC, you've done a great job for us, but we really want you to build an advanced semiconductor fab in the United States for supply resiliency.’

The pandemic had not happened yet, so we didn't quite know what they were really after, but they really were after supply resiliency. And we said, are you sure? That's going to be a really long time. It's going to be very expensive, it's very difficult. We don't have any our suppliers here, but we don't say no to our customers. We try to find ways to say yes, and we did a lot of due diligence. We went to multiple states, we showed our customer how expensive it was going to be, and they said, yes, we still really want you to build in the United States.

It's a good thing that we listened to our customer because a pandemic happened, and supply shortages were throughout the supply chain, and geopolitics came into play. So, in 2020, at the height of pandemic, TSMC committed to build its first fab, only one fab at the time, at about $12 billion, which we had underestimated and had to increase that investment to about $40 billion. Then the government said, ‘We want you to build (fabs) two and three with the most advanced nodes.’ And so that initial investment went from $12 to $40 to $65 billion just for the first three fabs. We broke ground in 2021, and we ended up having to do a lot of research to be able to get going, and it was difficult. But we persevered, and we caught up, so we are now in production with our most advanced node in scale in the United States and for technology, and that is in production in our fab one facility.

Fab two is getting up and running. Fab three, we broke ground, and in (March 2025), our chairman and CEO, Dr. C.C. Wei, he went to Washington and he committed another $100 billion to this site in Arizona, which would have a total of six fabs and two advanced manufacturing packaging facilities, as well as an R and D center. So we're just getting started in Arizona with just our first fab one, which isn't even really at full production yet.

Now, just to kind of put in perspective how much money that is, I looked up a couple of references. The International Space Station is listed as the most expensive product that mankind is built. It was a $100 to $150 billion estimate. $160 5 billion is just short of what the entire GDP for Ukraine as a country is. And I also like to reference the (NFL) stadium in Arizona. It’s only about $500 million. So the facility that we're building in Arizona for TSMC is 330 stadiums. It’s going to take us a decade, probably, to build all of that out depending upon how fast we can get our workforce, how fast our customers want us to build and how much demand there is for the product.

What kind of skills should students develop to become part of the semiconductor workforce and potentially join TSMC? 

Castanares: We need a pipeline of great engineering students and interdisciplinary backgrounds. I know that the University of Illinois Urbana-Champaign is going to produce some great students, and we are going to leave the teaching of those students, of the basics and fundamentals, to you. What we can offer is opportunities in terms of internships, support and mentorships — maybe even research projects.

For students going into the semiconductor industry now, it is something that just requires so much precision, but at the same time, requires so much collaboration. Of course, we look for the best and the brightest. We look for people who have taken the right courses, who've done the right coursework and have experience, but we also look for communication skills. Are they able to stand up at our daily operations meeting and talk about the problem statement and the solution and how they got their methodology? Can you do that in three minutes and be able to influence the management team for additional resources?

Those communication skills are really, really important. My team has done a great job to be able to bring our own coursework of how to do a PowerPoint presentation in front of TSMC management. That type of thing — students really need to understand that is just as important (as other skills).

The collaboration is really important because everything is interconnected.  You can't have a great transistor without having a way to connect it on the back end. So you've got to be able to talk with the module engineers and the equipment engineers. How do you collaborate to make sure that those defects are going to be as little as possible? How are you going to get to the next level of purity? How can we collaborate in terms of reducing water usage?

All those things require tens if not hundreds of people working together and collaborating. So those are things that I really want to emphasize, that students need to make sure that they have those types of skills, along with the background and the domain knowledge that they bring.

What other advice would you give to students who want to be successful in the semiconductor industry? 

Castanares: The pace is so fast that students these days have to adapt. The adaptable survive. Things are going to change very, very quickly, especially with AI. 

You don't know what the changes are going to be sometimes. You have to be willing, with the right attitude and mindset, to adapt and let go of things that aren't working and adapt to the new thing. Constantly learn and act upon what the situation really requires. If I bring it down to acronyms — adapt, ask and attitude. Those are really the things that I think students can take away to be successful.

What is a myth students might see about the semiconductor industry that you would like to debunk? 

Castanares: Oh, there are so many. People think manufacturing is boring assembly line work — it absolutely is not. It is so difficult to do. You've got a new problem every day, sometimes every hour. Also, that manufacturing is not research and development. Not true — because TSMC is a foundry, when our customers say, I don't want 15 layers of metal. I want 21,’ — that's R and D! When they say, ‘I know junction temperature for this transistor is this, but we want to overdrive at 20%.’ That's R and D to make sure that you manufacture that at scale for your customer.

The other myth is that TSMC is only in Taiwan. We’re here in Arizona and in Washington state. We’ve got offices everywhere. We would love to see more and more people from all over the U.S. think about TSMC as a place to grow and stay their entire career and contribute to a really fundamental part of our lives in technology.

AI is a constantly evolving tool in today's world, and some students have concerns about the availability of semiconductor manufacturing and engineering jobs to them. Should they have any worries?

Castanares: I think that there will always be jobs for people, as long as you adapt and have a good attitude, and can take on the next technology and use it to help you do your job better. Robotics are already in play. We’ve got lots of customers that are putting chips together for robotics, for autonomous driving. There are many different applications that are being built right now. 

It's actually much more difficult than it seems and it's going to take a while. In the meantime, students and people in the workforce now should not be afraid that it’s going to replace you. Can it help me do a better job? How can it take away all the repetitive, boring things that I don't really want to do so that I can focus on the more value-added things that only I can do? Using it just as another tool to do the more value-added things, I think, is the way I continue to think about it.

Illinois Grainger Engineering Affiliations 

Rashid Bashir is an Illinois Grainger Engineering professor of bioengineering in the Department of Bioengineering. He serves as dean of The Grainger College of Engineering. Bashir is affiliated with the Department of Materials Science and Engineering, the Holonyak Micro & Nanotechnology Lab and the Materials Research Laboratory. He holds the Grainger Distinguished Chair in Engineering appointment.

Qing Cao is an Illinois Grainger Engineering associate professor of materials science and engineering in the Department of Materials Science and Engineering. He is affiliated with the Department of Electrical and Computer Engineering, Department of Chemistry, Materials Research Laboratory and Holonyak Micro and Nanotechnology Lab. 

Nancy Sottos is an Illinois Grainger Engineering professor of materials science and engineering and serves as head of the Department of Materials Science and Engineering. She also serves as a Center for Advanced Study professor and holds a Swanlund Endowed Chair appointment.