ON Semiconductor and Motorola Laboratories Fabricate GaAs VFET MOSFET

A team of engineers with ON Semiconductor (Phoenix, AZ) and Motorola Laboratories (Tempe, AZ) have fabricated a GaAs VFET power MOSFET using only five mask levels and an implanted gate process. Performance of the device includes a specific on-resistance of 0.25 milliohm-centimeters-squared and a blocking voltage of 8.5V. The delay time for this device is 13.9 picoseconds.

The low manufacturing costs of this device are expected to make it competitive with silicon devices for high-performance power-switching applications such as synchronous rectification and battery-pack protection switches. The prototype device shows an on-resistance of 0.29ohms with a gate bias of 1V.

GaAs power MOSFETs are expected to offer several advantages compared with silicon-based devices, including lower on-resistance, smaller die sizes, faster switching and lower capacitance. Until now, however, GaAs devices have been more complex to produce and have required larger die sizes, resulting in higher costs compared with silicon. Several of those disadvantages, most notably cost, have been overcome with the development of the new manufacturing process.

This development was reported in the IEEE Electron Device Letters. No commercialization plans have been announced.