TY - JOUR
T1 - Dopant activation process in Mg-implanted GaN studied by monoenergetic positron beam
AU - Uedono, Akira
AU - Tanaka, Ryo
AU - Takashima, Shinya
AU - Ueno, Katsunori
AU - Edo, Masaharu
AU - Shima, Kohei
AU - Kojima, Kazunobu
AU - Chichibu, Shigefusa F.
AU - Ishibashi, Shoji
N1 - Funding Information:
This work was supported by MEXT-Program for Creation of Innovative Core Technology for Power Electronics (JPJ009777). A part of this work was also supported by the MEXT-Program for Research and Development of Next-Generation Semiconductor to Realize Energy-Saving Society (JPJ005357) and JSPS KAKENHI (21H01826).
Publisher Copyright:
© 2021, The Author(s).
PY - 2021/12
Y1 - 2021/12
N2 - A process for activating Mg and its relationship with vacancy-type defects in Mg-implanted GaN were studied by positron annihilation spectroscopy. Mg+ ions were implanted with an energy of 10 keV, and the Mg concentration in the subsurface region (≤ 50 nm) was on the order of 1019 cm−3. After the Mg-implantation, N+ ions were implanted to provide a 300-nm-deep box profile with a N concentration of 6 × 1018 cm−3. From capacitance–voltage measurements, the sequential implantation of N was found to enhance the activation of Mg. For N-implanted GaN before annealing, the major defect species were determined to Ga-vacancy related defects such as divacancy. After annealing below 1000 °C, the clustering of vacancies was observed. Above 1200 °C annealing, however, the size of the vacancies started to decrease, which was due to recombinations of vacancy clusters and excess N atoms in the damaged region. The suppression of vacancy clustering by sequential N-implantation in Mg-implanted GaN was attributed to the origin of the enhancement of the Mg activation.
AB - A process for activating Mg and its relationship with vacancy-type defects in Mg-implanted GaN were studied by positron annihilation spectroscopy. Mg+ ions were implanted with an energy of 10 keV, and the Mg concentration in the subsurface region (≤ 50 nm) was on the order of 1019 cm−3. After the Mg-implantation, N+ ions were implanted to provide a 300-nm-deep box profile with a N concentration of 6 × 1018 cm−3. From capacitance–voltage measurements, the sequential implantation of N was found to enhance the activation of Mg. For N-implanted GaN before annealing, the major defect species were determined to Ga-vacancy related defects such as divacancy. After annealing below 1000 °C, the clustering of vacancies was observed. Above 1200 °C annealing, however, the size of the vacancies started to decrease, which was due to recombinations of vacancy clusters and excess N atoms in the damaged region. The suppression of vacancy clustering by sequential N-implantation in Mg-implanted GaN was attributed to the origin of the enhancement of the Mg activation.
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U2 - 10.1038/s41598-021-00102-2
DO - 10.1038/s41598-021-00102-2
M3 - Article
C2 - 34667191
AN - SCOPUS:85117734387
VL - 11
JO - Scientific Reports
JF - Scientific Reports
SN - 2045-2322
IS - 1
M1 - 20660
ER -