Effect of dimethylhydrazine on p-type conductivity of as-grown Mg-doped GaN

초록

Mg dopants in GaN need post-growth thermal activation to be activated. However, it was observed that GaN growth with dimethylhydrazine (DMHy) resulted in p-type conductivity without activation. The reduction of NH3 flow by adding DMHy resulted in a vary low hydrogen concentration of 2.8 x 10(17) cm(-3) in Mg-doped GaN, which was even lower than the hole concentration. The low-temperature infrared transmittance spectra also showed that many hydrogen atoms were captured by incorporated carbon impurities. the combined effect of low concentration of hydrogen at carbon impurities is attributed to the p-type conductivity of as-grown Mg-doped GaN when a maximum of DMHy and NH3 was used for group V sources. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

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