Nearly Perfect Electrical Activation Efficiencies from Silicon-Implanted Al _x Ga_{1− x} N with High Aluminum Mole Fraction

摘要

Electrical activation studies of Al _x Ga_1−x N (x = 0.45 and 0.51) implanted with Si for n-type conductivity have been made as a function of ion dose and anneal temperature. Silicon ions were implanted at 200 keV with doses ranging from 1 × 1014 cm−2 to 1 × 1015 cm−2 at room temperature. The samples were subsequently annealed from 1150°C to 1350°C for 20 min in a nitrogen environment. Nearly 100% electrical activation efficiency was successfully obtained for the Si-implanted Al_0.45Ga_0.55N samples after annealing at 1350°C for doses of 1 × 1014 cm−2 and 5 × 1014 cm−2 and at 1200°C for a dose of 1 × 1015 cm−2, and for the Al_0.51Ga_0.49N implanted with silicon doses of 1 × 1014 cm−2 and 5 × 1014 cm−2 after annealing at 1300°C. The highest room-temperature mobility obtained was 61 cm2/V s and 55 cm2/V s for the low-dose implanted Al_0.45Ga_0.55N and Al_0.51Ga_0.49N, respectively, after annealing at 1350°C for 20 min. These results show unprecedented activation efficiencies for Al _x Ga_1−x N with high Al mole fractions and provide suitable annealing conditions for Al _x Ga_1−x N-based device applications.