32. Field-Effect Transistors 2

Ga₂O₃ has exploded onto the semiconductor landscape for next-generation power electronics because its enticing material properties, most notably a large critical field strength stemming from its ultrawide bandgap, promise miniaturized circuits and systems with high conversion efficiency. Intense pursuit of Ga₂O₃ power devices galvanized by the demonstration of a high-voltage Ga₂O₃ field-effect transistor (FET) in 2012 has brought about tremendous advancements in this new technology, whose strong radiation tolerance and high thermal stability also befit harsh-environment applications that impose stringent reliability requirements. This chapter reviews the designs and properties of various types of depletion- and enhancement-mode Ga₂O₃ FETs—which have predominantly been lateral devices—for power switching and radiation-hard electronics. The development of vertical Ga₂O₃ transistors based on a low-cost, highly manufacturable ion implantation doping process will also be presented.