Schottky diodes based on monocrystalline Al/AlGaN/GaN heterostructures for zero-bias microwave detection

The microwave properties of novel all-epitaxial Al/AlGaN/GaN low-barrier Schottky diodes with near-surface polarization-induced delta-doping are studied. An original technique for on-wafer microwave measurements of test structures is used. The possibility of development of a highly sensitive zero-bias microwave detector based on a planar low-barrier metal-semiconductor-metal heterostructure, which does not require the formation of ohmic contact of the semiconductor with the metal, is demonstrated. Estimates show that the cutoff frequency of such a detector can reach approximately 100 GHz for relevant values of the detecting contact area about 10 $\mu$m$^2$.