Large-signal performance of deep submicrometer AlGaN/AlN/GaNHEMTs with a field-modulating plate

This is the first time that the microwave performance of a 0.1-/spl mu/m gate in a silicon nitride window opening, with a field-modulating plate on an AlGaN/AlN/GaN heterojunction structure, is reported. The material structure was grown by organometallic vapor phase epitaxy on SiC substrates with an averaged channel sheet resistance of 313.5 ohms/square. Approximately 80-nm-thick plasma-enhanced chemical vapor deposition silicon nitride is used as the dielectric between gate metal extension and semiconductor surface. Transistors of a total gate width of 250 /spl mu/m and a 0.1 /spl mu/m gate footprint, with a 0.36 /spl mu/m long overhang on top of the silicon nitride, can be operated at a drain bias of 40-V high. Output power density of 9.5 W/mm, with 36% power-added efficiency in class AB regime, was demonstrated at 10 GHz in a continuous wave power measurement.