Electrical and optical characterization studies of lower dose Si-implanted AlxGa1-xN

초록

Electrical and optical activation studies of lower dose Si-implanted AlxGa1-xN (x = 0.14 and 0.24) have been made systematically as a function of ion dose and anneal temperature. Silicon ions were implanted at 200 keV with doses ranging from 1 x 10(13) cm(-2) to 1 x 10(14) cm(-2) at room temperature. The samples were proximity cap annealed from 1,100 degrees C to 1,350 degrees C with a 500-angstrom-thick AlN cap in a nitrogen environment. Nearly 100% electrical activation efficiency was obtained for Al0.24Ga0.76N implanted with a dose of 1 x 10(14) cm(-2) after annealing at an optimum temperature around 1,300 degrees C, whereas for lower dose (<= 5 x 10(13) cm(-2)) implanted Al0.24Ga0.76N samples, the electrical activation efficiencies continue to increase with anneal temperature up through 1,350 degrees C. Seventy-six percent electrical activation efficiency was obtained for Al0.14Ga0.86N implanted with a dose of 1 x 10(14) cm(-2) at an optimum anneal temperature of around 1,250 degrees C. The highest mobilities obtained were 89 cm(2)/Vs and 76 cm(2)/Vs for the Al0.14Ga0.86N and Al0.24Ga0.76N, respectively. Consistent with the electrical results, the photoluminescence (PL) intensity of the donor-bound exciton peak increases as the anneal temperature increases from 1,100 degrees C to 1,250 degrees C, indicating an increased implantation damage recovery with anneal temperature.

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