IISc Team Develops First Indigenous GaN Power Switch

Introduction

In a significant leap forward, researchers at the Indian Institute of Science (IISc) have achieved a groundbreaking milestone by developing a fully indigenous gallium nitride (GaN) power switch. This achievement holds immense potential for revolutionizing various electronic devices, including power converters for electric vehicles, laptops, ultrafast chargers, and wireless communications systems.

The GaN Advantage

Gallium nitride (GaN) transistors excel over silicon-based ones, offering superior performance and efficiency. They’re set to replace silicon in various electronic applications due to higher speed, better power handling, and improved efficiency. GaN is ideal for ultrafast chargers, power converters, and has applications in space and military technologies like radar systems.

Gallium Nitride: Next-Gen Semiconductor That Could Revolutionize Electronics

“It is a very promising and disruptive technology. But the material and devices are heavily import-restricted … We don’t have gallium nitride wafer production capability at commercial scale in India yet. The know-how of manufacturing these devices is also a heavily-guarded secret with few studies published on the details of the processes involved”

~Digbijoy Nath, Associate Professor at CeNSE and corresponding author of the study published in MicroElectronic Engineering.

The Journey to Indigenous GaN Power Switch

The development of the indigenous GaN power switch was achieved through meticulous efforts encompassing material growth, device fabrication, and packaging. The entire process was carried out in-house at the Centre for Nano Science and Engineering (CeNSE), IISc, marking a significant stride towards self-sufficiency in the domain of advanced electronic components.

Key Steps in GaN Power Switch Development

Material Growth and Device Fabrication:
The IISc team utilized a metal organic chemical vapour deposition technique refined over a decade to grow GaN alloy crystals layer by layer on a silicon wafer. This process was crucial for fabricating a multi-layered transistor.

Collaboration for Electrical Circuit Design:
The researchers joined forces with the Department of Electrical Engineering (EE). Together, they combined GaN and off-the-shelf silicon transistors. This fusion enabled the power switch to operate in the crucial “enhancement mode” necessary for chargers and adapters.

Testing and Performance Evaluation:
After meticulous packaging and testing, the team validated the device’s performance. The GaN power switch exhibited a switching time of approximately 50 nanoseconds between on and off operations, showcasing its comparable performance to state-of-the-art commercially available switches.

Two-inch GaN-on-silicon wafer with power transistors, developed at CeNSE, IISc (Photo: Ashutosh Vishwakarma)

Future Prospects and Scalability

In the future, the researchers aim to increase the size of the GaN power switch for handling higher currents. They also intend to create a versatile power converter that can adjust voltages, broadening the applications of this indigenous GaN technology.

From left to right: Srinivasan Raghavan, Manish Mandal, Rijo Baby, Kaushik Basu, Digbijoy N Nath (Photo: Ashutosh Vishwakarma)

“If you look at strategic organisations in India, they have a hard time procuring GaN transistors … It is impossible to import them beyond a certain quantity or power/frequency rating. This is essentially a demonstration of indigenous GaN technology development.”

~Digbijoy Nath, Associate Professor at CeNSE and corresponding author of the study published in MicroElectronic Engineering.

Conclusion

The indigenous GaN power switch is a testament to India’s advancing electronic capabilities. It showcases expertise in GaN technology and tackles import restrictions. This indigenous technology promises to reshape modern electronics, promoting self-reliance and tech advancement in India.