High-Powered Inventor


Dr. Jayant Baliga (BT/EE/1969) is a Distinguished University Professor in the Department of Electrical and Computer Engineering, and Director of the Power Semiconductor Research Center at North Carolina State University. He was conferred the Distinguished Alumnus Award in 2000.

Prof. Jayant Baliga.
Dr. Jayant Baliga.

He received the M.S. and Ph.D degrees from Rensselaer Polytechnic Institute in 1971 and 1974, respectively. While working at General Electric, he had the idea of integrating MOS and bipolar device technologies, leading to the invention of the insulated-gate bipolar transistor (IGBT).

The IGBT is a semiconductor device that is used extensively in controlling high power-levels, because of its high efficiency and fast switching. It is used in everything from compact fluorescent lamps, refrigerators and vehicle ignition systems to industrial robots and bullet trains. Its use in compact portable defibrillators saves tens of thousands of lives every year. It is also essential in wind- and solar-power generation systems. With such a wide variety of applications, the IGBT has enabled enormous savings in energy, and hence, money. And just as importantly, carbon dioxide emissions.

He is also a pioneer in the field of wide-bandgap semiconductors, which overcome the limitations of silicon. He came up with an equation, now called Baliga’s Figure of Merit, that predicts the performance enhancement one can obtain by changing the properties of the material used. Later, he built the first high-voltage silicon carbide devices.

In 1997, Scientific American named him as one of the “eight heroes of the semiconductor revolution”. He has over 100 U.S. patents and has authored or edited 18 books. Among his numerous honours are the IEEE Medal of Honor, and the National Medal of Technology and Innovation – the highest recognition given to an engineer by the U.S. government.

He spoke to T5E about his life and career.

Tell us about your upbringing. What were your childhood influences?

I grew up in Jalahalli on the outskirts of Bangalore during my high school years. Although a rural setting in the 1960s, I had a privileged upbringing because my father was the Chairman and Managing Director of Bharat Electronics Limited. (BEL). As an early electronics engineer, my father was a founding President of the Institute of Radio Engineers (IRE) which later merged with the IEEE. My home had a better electrical engineering library than most universities in India. I was exposed to ideas in the electrical engineering field from an early age and my father was an excellent role model. These circumstances convinced me to become an electrical engineer.

Any particular memories of your student days here at IIT Madras? I believe you received the medal for being the top EE graduate. You’ve also been conferred the Distinguished Alumnus Award by IIT Madras.

My memories at IIT Madras have been documented in the “Reflections” book. Even though I was the top-ranked student from my high school, I quickly found out that most students in my class had superior intellect and ability to grasp concepts. I felt that I could be competitive only by working much harder than most students. This led to my maintaining a rigorous study schedule free of distractions including the popular weekly cinema shown at the Open Air Theatre. This effort culminated in my getting the Philips India Medal and the Special Merit Medal as class valedictorian at graduation.

Tell us a little about the invention you’re most well-known for, the insulated-gate bipolar transistor (IGBT).

The IGBT was invented by me while working at the General Electric Corporate Research and Development Center in Schenectady, New York. There were many people skeptical about its viability at that time. However, I was able to commercialize the device in a remarkably short ten-month time frame. I also developed a method to prevent device failure from its parasitic thyristor and a unique method to control its switching speed. These breakthroughs allowed its widespread use within GE in the motor drives, refrigeration, appliance controls, lighting, and even the medical business. The large impact of my innovation on GE products led to conferment of the company’s highest award, the Coolidge Fellowship. At the age of 35, I was the youngest person to be given this prestigious recognition at that time.

An IGBT module.
An IGBT module. Image Credit:ArséniureDeGallium (2005) [GFDL or CC-BY-SA-3.0], via Wikimedia Commons

You also have over a hundred patents and have founded companies to commercialize your inventions. Could you tell us about them?

When I left GE in 1988, I had acquired 60 U.S. patents including many seminal patents on the IGBT structure. After joining North Carolina State University (NCSU), I started an industrial consortium called the Power Semiconductor Research Center (PSRC). I created a membership structure at PSRC that allowed my filing for patents resulting in getting 47 U.S. patents on advanced power-device technology. In 1998, the NCSU Foundation launched a venture fund to commercialize innovations made at the university. Since I had generated the largest number of patents at the university, the venture fund approached me to create spin-off companies to make products from my inventions. My Trench MOS Barrier Schottky (TMBS) rectifier invention was commercialized through my company Micro-Ohm Corporation in 1999. It has become the most successful new rectifier created in the last 25 years. My invention called the Silicon super-linear RF power MOSFET was commercialized at my company Silicon Wireless Corporation in 2002. It was benchmarked as the best technology for cellular base station applications. My SSFET and JBSFET inventions were commercialized at my company Silicon Semiconductor Corporation, in 2004, for providing power to microprocessors. My GDMOSFET invention was licensed for commercialization by my company Giant Semiconductor Corporation in 2006. I am pleased that all of these innovations are available as products today.

You spent 15 years at GE. This is one of the features of the research landscape in the U.S. — the private research labs which support basic and applied research. Do you think the private industry in India should be doing more to support research?

In the U.S., large corporations have moved away from funding basic research and now focus primarily on product-driven research and development. Basic research has been redirected to universities with most of the funding coming from agencies such as the National Science Foundation. Private industry interacts with university researchers to exploit the work on basic research.  A similar model may be possible in India.

Where would you say India stands globally in terms of research in semiconductor devices and also the semiconductor industry?

To my knowledge, there has not been much research activity in India on semiconductor devices until recently due to lack of infrastructure that is very expensive to install and maintain. However, this seems to be improving. I saw an impressive clean room facility for nanotechnology set up at the Indian Institute of Science during my last visit to India in December 2012. There is no semiconductor foundry set up in India at this time. This hinders product development and production in India by small and large companies.

Globally, where would you say the semiconductor research and the semiconductor industry is headed?

In the case of power semiconductor devices, the IGBT produced a revolutionary advancement in power electronics technology and its applications when I invented and commercialized the device in 1980. In the same year, I developed a theory that predicted a thousand-fold enhanced performance of power devices by replacing silicon with wide-bandgap semiconductors like silicon carbide. In the 1990s, this theoretical prediction was experimentally verified at my PRSC research center. After that, many companies began to investigate this material resulting in products by 2005. Just this year, President Obama announced at new manufacturing initiative to accelerate commercialization of wide-bandgap semiconductor based power electronics. This initiative is being led by NCSU and will create the next generation of power devices with high impact on power electronics.

Finally, what advice or message would you give to the present students at IIT Madras?

The advice I give to students is to keep an open mind to discover new ideas. It may look like all the good ideas have already been created. Even in the case of power semiconductor devices, it looked like a mature field with little innovation happening when I started working in it in 1974. However, the many innovations that I proposed and commercialized have made it a dynamic and vibrant field of activity with ever-increasing social impact. Students should take inspiration from this and be willing to get passionate about their ideas. There will be many skeptics, as in my case. But if you truly believe in the merits of your idea and work hard to make it successful, you can make a major difference in the lives of billions of people around the world.

Write a Comment

Your email address will not be published. Required fields are marked *