Gate Injection Transistor (GIT)—A Normally-Off AlGaN/GaN Power Transistor Using Conductivity Modulation

We have developed a normally-off GaN-based transistor using conductivity modulation, which we call a gate injection transistor (GIT). This new device principle utilizes hole-injection from the p-AlGaN to the AlGaN/GaN heterojunction, which simultaneously increases the electron density in the channel, resulting in a dramatic increase of the drain current owing to the conductivity modulation. The fabricated GIT exhibits a threshold voltage of 1.0 V with a maximum drain current of 200 mA/mm, in which a forward gate voltage of up to 6 V can be applied. The obtained specific ON-state resistance ($R_{ \scriptstyle{\rm ON} } \cdot A$) and the OFF-state breakdown voltage ($\hbox{BV}_{\rm ds}$) are 2.6 $\hbox{m}\Omega\cdot \hbox{cm}^{2}$ and 800 V, respectively. The developed GIT is advantageous for power switching applications.