Recently, in a collaborative effort together with Fujitsu Laboratories Limited, Fujitsu Semiconductor has been engaging in technical development initiatives, such as developing a process technology for growing high quality GaN crystals on a silicon substrate, developing device technologies, such as optimizing the design of electrodes to control the rise of on-resistance during switching, and devising a circuit layout for power supply units that can support the high-speed switching of GaN-based devices. These results have enabled Fujitsu Semiconductor, in a test circuit using a GaN power device, to succeed in achieving conversion efficiency that exceeds the performance of conventional silicon devices. Fujitsu Semiconductor also prototyped a power supply unit for servers equipped with a GaN power device for the power factor correction circuit and successfully achieved output power of 2.5kW.

Figure 2. GaN Power Device Prototype (TO247 Package)

Fujitsu Semiconductor views its success in these results as opening a path to high-voltage, large-current applications for its GaN power devices.

Fujitsu Semiconductor has recently completed setting up a mass-production line for 6-inch wafers at its Aizu-Wakamatsu plant, and will begin full-scale production of GaN power devices in second half of 2013. Moving forward, by offering GaN power devices optimized for customer applications and technology support for circuit designs, Fujitsu Semiconductor will support the development of low-loss, highly-compact power supply units suited to a wide range of uses. Fujitsu Semiconductor is aiming to achieve approximately 10 billion yen in sales of GaN power devices in fiscal 2015.