Impact of Mg Doping on the Properties of P-Type Al-Rich AlGaN Film

This study investigates the effects of Mg doping on the properties of p-type AlGaN with high aluminum (Al) composition. High Mg doping causes to the rough surface and even hillocks due to the compressive strain introduced by Mg. The SIMS data shows that the high Mg doping leads to the formation of polarity inversion domains with other impurities and the donor-acceptor pair (DAP) peaks enhances strongly in CL spectrum. The hall measurement shows that the hopping conduction dominates in these p-type AlGaN, and the conductivity first increases and then decreases with increasing Mg doping. The p-type AlGaN (Al~0.6) with the high conductivity of 0.112 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{s}\cdot \text{cm}^{-1}$</tex> at room temperature is achieved. This study provides a highly conductive high-Al-content p-type AlGaN for improving the performance of deep ultraviolet optoelectronic devices.