Panasonic develops Insulated-Gate GaN power transistor

ANI | Updated: Feb 23, 2018 15:34 IST

Osaka [Japan], Feb 23 (ANI): Consumer electronics leader Panasonic on Friday announced that they have developed an insulated-gate gallium nitride (GaN) power transistor, capable of continuous stable operation with no variation in its threshold voltage.

This technology makes it possible to further increase in the speed of GaN power transistors, enabling the miniaturisation of various electronic equipment.

Metal Insulator Semiconductor (MIS) type GaN power transistor is anticipated for practical uses as the next-generation power devices.

Meanwhile, Panasonic has been continuing its research on MIS gate structure as a future technology to further increase its operation speed.

However, hysteresis occurs in conventional MIS type GaN power transistors, and high-speed switching operations with a high current and a high voltage had not yet been confirmed.

For the first time, the company was able to confirm the continuous stable operation of MIS type GaN power transistors, which are required for future ultrafast GaN power devices, at a current of 20 A.

With a significant increase in switching frequency, the miniaturisation of peripheral passive components becomes possible.

Highly efficient operation and miniaturisation of various power conversion circuits, such as power supplies for servers and base stations, can be achieved with this technology.

Enabling the operation at higher frequencies leading to further miniaturisation of equipment, the new transistor is expected to expand the GaN power transistor market.

Panasonic's newly developed GaN power transistors have the following features:

- Continuous stable operation: Maximum gate voltage of +10 V.

- High current and high voltage operation: Drain current of 20 A and breakdown voltage of 730 V.

- High-speed switching: OFF operation time of 1.9 ns and ON operation time of 4.1 ns.

This achievement is the result of collaborative research with Assistant Professor Takuji Hosoi and Professor Heiji Watanabe of Osaka University, and Professor Tamotsu Hashizume of Hokkaido University, partly supported by cross-ministerial Strategic Innovation Promotion Program (SIP), "Next-Generation Power Electronics" (funding agency: NEDO) of Council for Science, Technology and Innovation (CSTI) of the Cabinet Office, Government of Japan.

Product features:

- Continuous stable operation:

For MIS type GaN power transistors, the issue was that a hysteresis attributed to electron traps within the gate insulator was often observed in the drain current characteristics resulting in a variation of the threshold voltage.

In this development, the device structure, as well as the fabrication process, was improved to suppress such hysteresis.

As a result, it has become possible to achieve continuous stable operation with a gate voltage up to +10 V.

- High current and high voltage operation:

In GaN power devices, achieving both a normally-off operation and a high-current operation was an issue. In this development, the introduction of a recessed gate structure that formed directly under the gate electrode made it possible to achieve a high-current operation up to 20 A while maintaining a normally-off operation.

In addition, a high breakdown voltage of 730 V was achieved by increasing the distance between the gate and the drain electrodes.

- High-speed switching:

GaN power devices with a horizontal structure possess a small parasitic capacitance, making high-speed switching possible.

In order to operate at a higher speed during switching operations, it is necessary to apply a higher gate voltage and perform switching operations in a shorter time. In this development, faster switching is possible because a gate voltage up to +10 V can be applied. (ANI)