Power-switching beyond silicon: features of GaN devices

Abstract

The generation, transmission, and use of electric power require different forms of power conversion. The commonly used electronic circuits for power conversion utilize switching techniques and, consequently, are referred to as switch-mode power electronic circuits. Two types of semiconductor-based switches are widely used in these circuits: two-terminal rectifiers (diodes) and three-terminal controlled switches (transistors). Currently, many integrated circuit devices use Silicon as the main substrate, because silicon is easy to purify and crystallize. Moreover, it is cheaper than nearly most of other semiconductor material. Silicon becomes main semiconductor material in today’s developments of power-switching. However, silicon’s energy gap is not large enough, which is the limitation of realizing more functions. With the requirement of new material to break the boundary of material limitation, the third-generation semiconductor rise up. This article will discuss the ideal requirements of power switching and how these requirements were realized by GaN through the method of deriving equations. Meanwhile, comparing with advantages of GaN, this paper will point out the silicon’s shortages. Finally, discussing reasons why GaN did not substitute Si then become the main semiconductor material among diodes or transistors.