The characteristics of fluorinated gate dielectric AlGaN/GaN MIS-HEMT

抄録

In this letter, a normally-off AlGaN/GaN MIS-HEMT using fluorinated gate dielectric was presented. The fluorine ions were injected into the Al₂O₃ gate dielectric to obtain positive threshold voltage (V_th) as well as avoiding the plasma induced to the GaN channel layer. Moreover the maximum transconductance of fluorinated gate MIS-HEMT has been improved compared with the non-treated MIS-HEMT. Furthermore, the fluorine ions injected into the Al₂O₃ gate dielectric could decrease the trap states density (D_T) and time constant (τ_T) at the Al₂O₃/GaN interface. The normally-off MIS-HEMT showed a very high drain current of 507 mA/mm and V_th of 0.6V.