Toyoda Gosei Co., Ltd. has developed the world’s first 1.2 kV class power semiconductor device (a general term for power rectifier diodes, switching transistors, etc.) chip capable of large current operation exceeding 20 A. This was done using gallium nitride (GaN), a key material in blue LEDs, which has superior physical properties including the ability to withstand high voltages.
Using the crystal growth technology we have cultivated since 1986 in the development and production of blue LEDs, we began research for the development of device technology for power semiconductors using GaN in 2010. Previously, low loss MOSFETs (a type of transistor used in power devices*) of the 1.2 kV class were fabricated on GaN substrates and then empirically tested. We have now established wiring technology for the parallel operation of elements, successfully passing an electrical current exceeding 20 A in a vertical GaN transistor with a 1.5 mm square chip size. This is the first time that has ever been achieved, according to a Toyoda Gosei survey.
The developed technology are applied to circuits for the power controllers on hybrid vehicles that handle large amounts of power, and to power converters such as those in solar power generation, which promises significant contributions in making these devices more compact and efficient. We will continue research to increase the current capacity and test reliability with the aim of developing commercial applications by about 2018-2020 in collaboration with semiconductor and electronics manufacturers.