Improved RF power performance of AlGaN/GaN HEMT on silicon with planar distributed channel

ABS T R A C T AlGaN/GaN HEMTs with planar distributed channel were fabricated on a silicon substrate. With a standard ion implantation isolation process, the area between the ohmic contacts was divided into conductive and non-conductive regions. Compared to a conventional HEMT, simulations and experimental results indicate the decreased channel temperature and improved RF power performance in the distributed channel device, while there is no significant degradation in small signal characteristics. The fabricated multi-finger distributed channel devices with 0.65-mm gate periphery demonstrated a decrease in channel temperature from 186 degrees C to 162 degrees C, accompanied by a 15.6 % increase (from 3.2 W/mm to 3.7 W/mm) in output power density, and an 8 % increase (from 42.0 % to 50.0 %) in drain efficiency at 3.5 GHz.