A large-area power MOSFET designed for low conduction losses

A new power MOSFET has been fabricated that conducts 75 A with an on-state resistance of 0.012 ohm and blocks 60 V. The device may be used as a low-loss synchronous rectifier in efficient high-frequency power supplies or as a high-current power switch in applications such as emitter switching. The device design criteria include obtaining the largest possible fraction of the ideal blocking voltage and obtaining the minimum on-state resistance. Efficient utilization of the device area requires smaller feature size and shallower junction depths for low-voltage power MOSFETs than for high-voltage ones. The device reported on is 300 mils on a side and contains over 60,000 MOSFET cells in parallel. It has a gate width of more than 4 m. This device is larger and more complex than any previously reported power MOSFET. It provides an example of how power device processing techniques are approaching those of LSI circuit technology.