authors |
Wahl, U; Correia, JG; Costa, ARG; David-Bosne, E; Kappers, MJ; da Silva, MR; Lippertz, G; Lima, TAL; Villarreal, R; Vantomme, A; Pereira, LMC |
nationality |
International |
journal |
ADVANCED ELECTRONIC MATERIALS |
author keywords |
acceptor doping; amphoteric dopants; channeling; GaN; ion implantation; lattice location; Mg |
keywords |
MAGNESIUM-ION-IMPLANTATION; GALLIUM NITRIDE; DEFECTS; TOOL |
abstract |
Despite the renewed interest in ion implantation doping of GaN, efficient electrical activation remains a challenge. The lattice location of Mg-27 is investigated in GaN of different doping types as a function of implantation temperature and fluence at CERN's ISOLDE facility. The amphoteric nature of Mg is elucidated, i.e., the concurrent occupation of substitutional Ga and interstitial sites: following room temperature ultra-low fluence (approximate to 2 x 10(10) cm(-2)) implantation, the interstitial fraction of Mg is highest (20-24%) in GaN pre-doped with stable Mg during growth, and lowest (2-6%) in n-GaN:Si, while undoped GaN shows an intermediate interstitial fraction of 10-12%. Both for p- and n-GaN prolonged implantations cause interstitial Mg-27 to approach the levels found for undoped GaN. Implanting above 400 degrees C progressively converts interstitial Mg to substitutional Ga sites due to the onset of Mg interstitial migration (estimated activation energy 1.5-2.3 eV) and combination with Ga vacancies. In all sample types, implantations above a fluence of 10(14) cm(-2) result in >95% substitutional Mg. Ion implantation is hence a very efficient method to introduce Mg into substitutional Ga sites, i.e., challenges toward high electrical activation of implanted Mg are not related to lack of substitutional incorporation. |
publisher |
WILEY |
issn |
2199-160X |
year published |
2021 |
volume |
7 |
issue |
9 |
digital object identifier (doi) |
10.1002/aelm.202100345 |
web of science category |
10 |
subject category |
Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied |
unique article identifier |
WOS:000663379000001
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ciceco authors
impact metrics
journal analysis (jcr 2019):
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journal impact factor |
6.593 |
5 year journal impact factor |
6.831 |
category normalized journal impact factor percentile |
79.688 |
dimensions (citation analysis):
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altmetrics (social interaction):
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