TY - GEN
T1 - Control of vacancy-type defects in Mg implanted GaN studied by positron annihilation spectroscopy
AU - Uedono, Akira
AU - Dickmann, Marcel
AU - Egger, Werner
AU - Hugenschmidt, Christoph
AU - Ishibashi, Shoji
AU - Chichibu, Shigefusa F.
N1 - Funding Information:
This work was supported by the Council for Science, Technology and Innovation (CSTI)s, Cross-ministerial Strategic Innovation Promotion Program (SIP), “Next-generation power electronics” (funding agency: NEDO). A part of this work was also supported by JSPS KAKENHI Grant No. 16H06424 and 16H06427 and the MEXT “Program for research and development of next-generation semiconductor to realize energy-saving society”.
Publisher Copyright:
© 2020 SPIE.
PY - 2020
Y1 - 2020
N2 - Vacancy-type defects in Mg-implanted GaN were probed using monoenergetic positron beams. Mg+ ions were implanted to provide box profiles with Mg concentrations [Mg] of 1017-1019 cm-3. For as-implanted samples, the major defect species was determined to be Ga-vacancy (VGa) related defects such as divacancy (VGaVN) and/or their complexes with impurities. For Mg-implanted samples, an agglomeration of vacancies started at 800-1000°C annealing, leading to the formation of vacancy clusters such as (VGaVN)3. For the sample with [Mg]=1019 cm-3, the trapping rate of positrons to the vacancies decreased with increasing annealing temperature (≥1100°C), which was attributed to the change in the charge state of vacancy-type defects from neutral to positive (or negative to neutral) due to the activation of Mg. For Mg- and H-implanted samples, the hydrogenation of vacancy-type defects started after 800°C annealing. Comparing with the annealing behavior of defects for the samples without H-implantation, the clustering of vacancy-type defects was suppressed, which can be attributed to the interaction between Mg, H, and vacancies.
AB - Vacancy-type defects in Mg-implanted GaN were probed using monoenergetic positron beams. Mg+ ions were implanted to provide box profiles with Mg concentrations [Mg] of 1017-1019 cm-3. For as-implanted samples, the major defect species was determined to be Ga-vacancy (VGa) related defects such as divacancy (VGaVN) and/or their complexes with impurities. For Mg-implanted samples, an agglomeration of vacancies started at 800-1000°C annealing, leading to the formation of vacancy clusters such as (VGaVN)3. For the sample with [Mg]=1019 cm-3, the trapping rate of positrons to the vacancies decreased with increasing annealing temperature (≥1100°C), which was attributed to the change in the charge state of vacancy-type defects from neutral to positive (or negative to neutral) due to the activation of Mg. For Mg- and H-implanted samples, the hydrogenation of vacancy-type defects started after 800°C annealing. Comparing with the annealing behavior of defects for the samples without H-implantation, the clustering of vacancy-type defects was suppressed, which can be attributed to the interaction between Mg, H, and vacancies.
KW - Defect
KW - Doping
KW - GaN
KW - Ion implantation
KW - Positron annihilation
KW - Vacancy
UR - http://www.scopus.com/inward/record.url?scp=85082720638&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85082720638&partnerID=8YFLogxK
U2 - 10.1117/12.2541518
DO - 10.1117/12.2541518
M3 - Conference contribution
AN - SCOPUS:85082720638
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Gallium Nitride Materials and Devices XV
A2 - Fujioka, Hiroshi
A2 - Morkoc, Hadis
A2 - Schwarz, Ulrich T.
PB - SPIE
T2 - Gallium Nitride Materials and Devices XV 2020
Y2 - 4 February 2020 through 6 February 2020
ER -