High power performance AlGaN/GaN HEMT with 0.1 μm Y-shaped gate encapsulated with low-κ BCB

High power performance AlGaN/GaN HEMT devices with 0.1 μm Y-shaped gates encapsulated with low-κ BCB are reported. The maximum drain current and transconductance of the device are 1.15 A/mm and 350 mS/mm, respectively. The two-terminal breakdown voltage exceeds 30 V, which ensures a high operating voltage. Using the novel 0.1 μm low parasitic Y-shaped gate associated with AlGaN back barrier, a f
_T
of 90 GHz and a f
_max
of 170 GHz were obtained for the device. Through measurements of the W-band GaN MMIC PA, ability of 1.55 W/mm output power density was achieved for the device at frequency of 92 GHz. These outstanding performance indicates the devices are suitable for W-band MMIC applications.