GaN Heterostructure Barrier Diodes Exploiting Polarization-Induced $\delta$ -Doping

A GaN-based heterostructure barrier diode (HBD) similar to GaAs planar-doped barrier diodes is demonstrated. Instead of doping with impurities, the polarization-induced sheet charge at the III-nitride heterojunction behaves as an effective δ -doping. An AlGaN/GaN heterostructure is used for the demonstration. The rectifying characteristics of the polarization-induced GaN HBDs can be tuned by controlling the graded AlGaN thickness and composition. Such polarization-engineered HBDs can find applications in high-voltage and high-frequency electronics.