Efficient optical activation of ion-implanted Zn acceptors in GaN by annealing under 10 kbar N₂ overpressure

We continue our investigations into the optical activation of Zn-implanted GaN annealed under ever higher N ₂ overpressure. The samples studied were epitaxial GaN/sapphire layers of good optical quality which were implanted with a 10 ¹³ cm ^-2 dose of Zn ⁺ ions at 200 keV, diced into equivalent pieces and annealed under 10 kbar of N ₂- The N ₂ overpressure permitted annealing at temperatures up to 1250°C for 1 hr without GaN decomposition. The blue Zn-related photoluminescence (PL) signal rises sharply with increasing anneal temperature. The Zn-related PL intensity in the implanted sample annealed at 1250°C exceeded that of the epitaxially doped GaN:Zn standard proving that high temperature annealing of GaN under kbar N ₂ overpressure can effectively remove implantation damage and efficiently activate implanted dopants in GaN. We propose a lateral LED device which could be fabricated using ion implanted dopants activated by high temperature annealing at high pressure.