Vertical Ultra-Wide Bandgap Al_0.5Ga_0.5N P-N Memory Diodes

We reports vertical p-n memory diodes based on ultra-wide bandgap Al<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub>Ga<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub>N heterostructures on sapphire substrates. A conductive path with variable resistance is formed in the AlGaN p-n diode at a low trigger voltage of -47 V, thanks to the intentionally inserted heavily doped n-Al<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub>Ga<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub>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 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.