Electrical activation studies of Si-implanted GaN grown on sapphire have been made as a function of ion dose and anneal temperature. Silicon was implanted at 200 keV with doses ranging from 1×1013 to 5×1015 cm−2 at room temperature. The samples were annealed from 1100 to 1350 °C with a 500-Å-thick AlN cap in a nitrogen environment. Samples implanted with high doses (⩾1×1015 cm−2) have optimum anneal temperatures of around 1350 °C, exhibiting a nearly 100% electrical activation efficiency, whereas low dose (⩽5×1014 cm−2) samples exhibited lower activation efficiencies, but efficiencies increase with anneal temperature even after annealing at 1350 °C.

Comprehensive and systematic electrical and optical activation studies of Siimplanted GaN were made as a function of ion dose and anneal temperature. Silicon ions were implanted at 200 keV with doses ranging from 1 ϫ 10 13 cm Ϫ2 to 5 ϫ 10 15 cm Ϫ2 at room temperature. The samples were proximity-cap annealed from 1050°C to 1350°C with a 500-Å-thick AlN cap in a nitrogen environment. The optimum anneal temperature for high dose implanted samples is approximately 1350°C, exhibiting nearly 100% electrical activation efficiency. For low dose (Յ5 ϫ 10 14 cm Ϫ2 ) samples, the electrical activation efficiencies continue to increase with an anneal temperature through 1350°C. Consistent with the electrical results, the photoluminescence (PL) measurements show excellent implantation damage recovery after annealing the samples at 1350°C for 20 sec, exhibiting a sharp neutral-donor-bound exciton peak along with a sharp donoracceptor pair peak. The mobilities increase with anneal temperature, and the highest mobility obtained is 250 cm 2 /Vs. The results also indicate that the AlN cap protected the implanted GaN layer during high-temperature annealing without creating significant anneal-induced damage.

, respectively and annealed at 1350 °C for 2 min. The activation efficiency and mobility increase with anneal temperature, indicating an improved implantation damage recovery. The highest mobility obtained from the Si-implanted Al 0.25 Ga 0.75 N was 50 cm 2 /Vs for a dose of 1 × 10 15 cm −2 . The increase of photoluminescence intensities of band-edge luminescence and a broad green band was observed as the anneal temperature increases from 1200 to 1350 °C, indicating an excellent implantation damage recovery with increasing anneal temperature.

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