Electrical characterization of Si-ion implanted AlxGa1-xN annealed at lower temperatures

초록

Electrical activation studies of Si-implanted AlGa1-xN (x = 0.1 and 0.18) grown on sapphire substrate have been made as a function of anneal time, anneal temperature, and ion dose. Silicon implantation was done at room temperature with a dose ranging from 5 x 10(13) to 5 x 10(15) cm(-2) at 200 keV. The samples were proximity cap annealed from 1100 to 1250 degrees C for 5-40 min with a 500 angstrom-thick AlN cap in a nitrogen environment. The electrical activation efficiencies of 84% and 75% were obtained for the Al0.1Ga0.9N after annealing at 1200 degrees C for 40 min for a dose of 5 x 10(13) and 1 x 10(14) cm, respectively. For the Al0.18Ga0.82N, nearly 100% activation for a dose of 5 x 10(14) cm(-2) and 94% for a dose of 1 x 10(15) cm(-2) were achieved after annealing at 1250 degrees C and 1200 degrees C for 20 min, respectively. Both the activation efficiency and mobility increase with anneal time and anneal temperature, indicating an improved implantation damage recovery. The highest mobility obtained at room temperature is 89 cm/Vs for the Al0.1Ga0.9N samples having doses of 5 x 10(13) and 1 x 10(14) cm(-2) and annealed at either 1200 degrees C for 40 min or 1250 degrees C for 20 min. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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