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Codoping of gallium nitride for improved acceptor ionization has long been theorized; however, reduction to practice proves difficult via growth. Herein, implementation of codoping via ion implantation and symmetric multicycle rapid thermal annealing utilizing magnesium codoped with silicon or oxygen is demonstrated. Results show enhanced photoluminescence with both donor species but with an order of magnitude greater increase with concurrent p‐type hall for codoping with oxygen. Furthermore, the addition of nitrogen to balance stoichiometry suppresses defect photoluminescence signals. The incorporation of the donor and nitrogen demonstrates defect reduction beyond magnesium, only implants despite the additional implant dose and resultant damage with coimplantation. The enhanced hole concentrations evident with oxygen incorporation reveal important considerations for device design given unintentional doping during growth and future incorporation of ion implantation capabilities. [ABSTRACT FROM AUTHOR]

Ion implantation of magnesium for p‐type GaN presents many opportunities; however, activation has proven difficult due to the decomposition of GaN at relevant annealing temperatures. Herein, testing the efficacy of multiple in situ and ex situ caps based on aluminum nitride and silicon nitride for GaN protection during annealing is presented. Photoluminescence shows better activation for in situ metal organic chemical vapor deposition (MOCVD)‐grown aluminum nitride caps compared with ex situ sputtered aluminum nitride and the best performance by ex situ plasma‐enhanced chemical vapor deposition (PECVD) silicon nitride. Furthermore, only samples annealed at the highest temperatures tested show preferential growth of UV luminescence to yellow‐green luminescence reinforcing the need for better capping solutions and higher temperature annealing. [ABSTRACT FROM AUTHOR]

An Mg-implanted p-i-n diode was fabricated and characterized. Mg activation was achieved using the multicycle rapid thermal annealing technique with rapid heating pulses up to 1340 °C. The surface of the implanted GaN after annealing was smooth (0.94 nm RMS roughness) with growth steps evident as characterized by atomic force microscopy. The full width at half-maximum of the implanted GaN E2 Raman mode approaches that of the as-grown GaN after the annealing process, indicating that the annealing process is able to reverse most of the implantation damage. The Mg-implanted p-i-n diode exhibits rectification and a low leakage current of 0.11 μA cm−2 at a bias of −10 V. Under forward bias, light emission was observed from the p-i-n diode. The implantation and activation of Mg in a GaN-based device, demonstrated for the first time in this research, is a key enabling step for future optoelectronic and power electronic devices. Current-voltage characteristics of the Mg-implanted p-i-n diode with an inset of the device schematic. [ABSTRACT FROM AUTHOR]