Characteristics of AlGaN/GaN HEMT devices with SiN passivation

This paper demonstrates the effect of surface passivation on the DC and L-band power characteristics of doped AlGaN/GaN HEMT devices. Drain current and transconductance of AlGaN/GaN increase from 610 mA/mm to 690 mA/mm and 15O mS/mm to 170 mS/mm, whereas other measurements such as Hall and TLM show little change with SiN passivation. Output power dramatically increases from 0.59 W/mm to 1.45 mW/mm. The influence of the SiN layer on the bias dependence of the RF-output power is investigated.