Vertical Ultra-Wide Bandgap Al0.5Ga0.5N P-N Memory Diodes

We report vertical p-n memory diodes based on ultra-wide bandgap $Al_{{0}.{5}}$ $Ga_{{0}.{5}}$ N heterostructures on sapphire substrates. A conductive path with variable resistance is formed in the AlGaN p-n diodes at a low trigger voltage of $\text {-}47$ V, thanks to the intentionally inserted heavily doped n- $Al_{{0}.{5}}$ $Ga_{{0}.{5}}$ N layer at the p-n junction interface. A notable hysteresis phenomenon can be observed, characterized by repeatable write/erase program cycles. Consistent and repeatable switching performance across 100 cycles has been observed, verifying the stability of the conductive path in the vertical AlGaN p-n memory diodes. These results provide promising strategies and potential reference for developing robust and reliable memory devices based on III-nitride ultra-wide bandgap semiconductors.