DC and RF characteristic comparison of recessed-gate AlGaN/GaN HEMTs with CF4-based and Ch-based plasma gate recessing process

CF
₄
-based plasma recessed gate (CF
₄
-RGD) and Cl
₂
-based plasma recessed gate (Cl
₂
-RGD) AlGaN/GaN HEMTs were fabricated in this paper. CF
₄
-RGD showed higher DC and RF performance with a peak G
_m
of 383 mS/mm and f
_T
/f
_max
of 49/153GHz than Cl
₂
-RGD with a peak G
_m
of 352 mS/mm and f
_T
/f
_max
of 45/118GHz. Due to the outstanding and stable characteristics of CF4-RGD, CF4 plasma is a promising candidate for the gate recessing process in fabrication of GaN-based microwave applications.