2015 Volume 12 Issue 24 Pages 20150943
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 (Vth) 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 (DT) and time constant (τT) at the Al2O3/GaN interface. The normally-off MIS-HEMT showed a very high drain current of 507 mA/mm and Vth of 0.6 V.
