What it means to be the inventor of the IGBT

By Harry Fowle, Associate Editor, Electronic Specifier

The €1 million global award for technology recognised Baliga's pivotal role in the invention, development, and commercialisation of the Insulated Gate Bipolar Transistor (IGBT). Developed in the 1980s, the IGBT has been a key semiconductor device in improving the efficiency of electrical energy use and reducing petrol consumption and pollution over the last 40 years. By enhancing efficiency and lowering fossil fuel use and costs, the IGBT has significantly impacted the power industry. Over the past 30 years, this technology has cut global carbon dioxide emissions by over 82 gigatonnes (180 trillion pounds). This reduction is equivalent to offsetting the carbon dioxide emissions from all human activities for three years, based on the average emissions over the past 30 years.

Seeing his invention flourish

Baliga first discovered the IGBT-mode in an old MOS-gated four-layer thyristor structure that he fabricated in the 1977-78 period. He then took this mode of operation and expanded on it, applying it to high currents and voltages to create what would become the IGBT in 1980, leading to the modern patent we see today. The design was then proposed by Baliga, who at the time worked at General Electric (GE), to make the first devices in a manufacturing line alongside power MOSFETs, cutting short the development time from five years to less than one. His chip design and production process led to IGBT chips being manufactured in large quantities, and applied by GE engineers across various consumer, industrial, and lighting products.

“GE released an IGBT product in June of 1983, it found a huge number of other uses in all sectors of the economy,” says Baliga. “It had always been a dream of mine to create an innovation that would really benefit humanity, the impact of the IGBT truly exceeds my wildest dreams.”

Reminiscing on his personal favourite application of the technology, Baliga says: “My favourite applications for the IGBT are the electronic ignition system for energising spark plugs in gasoline powered cars, the adjustable speed drives for running motors, and the compact fluorescent lamps for lighting because they’ve generated huge consumer savings while eliminating an enormous amount of carbon dioxide emissions. An unexpected application for the technology which I love was building portable defibrillators using IGBTs to save thousands of lives.”

The man with the world's largest negative carbon footprint

Seeing his invention, and subsequent applications stemming from it, has been an amazing experience for Baliga, and is a dream come true for the Professor. The positive environmental impact it has had on the world today cannot be understated, and Baliga is happy to see this side of the invention being celebrated.

“I wrote this in my graduate school application. It was originally invented to make more applications practical at GE with increased energy efficiency. It has been particularly gratifying that this has had an enormous environmental impact as well.”

Looking ahead, Baliga hopes that humanity should gear itself towards becoming a more energy-efficient collective, something that would benefit all. “Collectively, humanity should give priority to energy efficiency when aspiring to raise living standards. We need a global commitment to replacing fossil fuel-based electricity production to renewable energy sources. The IGBT is an essential component in all renewable energy generation to deliver stable 50-60Hz electric power to home and factories. We need to replace gasoline powered vehicles with electric vehicles to eliminate carbon dioxide emissions. All the hybrid-electric and electric cars have been built using the IGBT to run the motors,” he says.

“The IGBT is an embedded technology that is hidden from the eyes of society. It quietly improves the quality of life for billions of people without their knowledge. The Millennium Technology Prize puts a spotlight on my innovation as one of most impactful engineering achievements in the last fifty years. It is wonderful to see the IGBT getting the recognition it richly deserves,” concludes Baliga.

This article originally appeared in the October'24 magazine issue of Electronic Specifier Design – see ES's Magazine Archives for more featured publications.