Diffusion and impurity segregation in hydrogen-implanted silicon carbide

Journal Article · Sat Jun 14 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4882996· OSTI ID:22304147

Kozubal, M.; Ratajczak, J.; Gołaszewska, K. ^[1]; Jakieła, R.; Dyczewski, J.; Wojciechowski, T. ^[2]; Celler, G. K. ^[3]

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1. Institute of Electron Technology, Al. Lotnikow 32/46, 02-668 Warsaw (Poland)
2. Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw (Poland)
3. Institute for Advanced Materials, Devices, and Nanotechnology (IAMDN)/Department of Materials Science and Engineering, Rutgers University, New Brunswick, New Jersey 08901 (United States)

Diffusion and segregation behavior of hydrogen and oxygen in silicon carbide subjected to H implantation and subsequent annealing were studied with a number of analytical techniques including Secondary Ion Mass Spectrometry (SIMS), Rutherford backscattering spectrometry in channeling geometry, field emission scanning electron microscopy, optical microscopy, cross-sectional transmission electron microscopy, and atomic force microscopy. H{sup +} implantation was carried out with energies of 200 keV, 500 keV, or 1 MeV to doses of 1 × 10{sup 16}, 1 × 10{sup 17}, or 2 × 10{sup 17} ion/cm{sup 2}, and thermal treatment was conducted in flowing argon for 1 to 2 h at temperatures of 740, 780, 1000, or 1100 °C. The process of migration and eventual loss of hydrogen in a point defect regime is postulated to proceed to a large extent through ionized vacancies. This conclusion was derived from the observed substantial difference in H mobilities in n- vs. p-type SiC as the population of ionized vacancies is governed by the Fermi-Dirac statistics, i.e., the position of the Fermi level. For higher doses, a well defined buried planar zone forms in SiC at the maximum of deposited energy, comprising numerous microvoids and platelets that are trapping sites for hydrogen atoms. At a certain temperature, a more or less complete exfoliation of the implanted layer is observed. For a 1 MeV implant heated to 1100 °C in nominally pure argon, SIMS profiling reveals a considerable oxygen peak of 10{sup 16} O atoms/cm{sup 2} situated at a depth close to that of the peak of the implanted H{sup +}. Similarly, 1100 °C annealing of a 200 keV implant induces the formation of a thin oxide (4 nm), located at the interface between the implanted layer and the substrate as evidenced by both SIMS and HRTEM. The measurements were taken on the part of the sample that remained un-exfoliated. In view of a lack of convincing evidence that a hexagonal SiC might contain substantial amounts of oxygen, further investigation is under way to elucidate its presence in the irradiation-damaged films.

• OSTI ID: 22304147
• Journal Information: Journal of Applied Physics, Vol. 115, Issue 22; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMIC FORCE MICROSCOPY
CHANNELING
DIFFUSION
FIELD EMISSION
FILMS
HYDROGEN IONS 1 PLUS
ION IMPLANTATION
ION MICROPROBE ANALYSIS
KEV RANGE 100-1000
MASS SPECTROSCOPY
MIGRATION
MOBILITY
OXYGEN
RUTHERFORD BACKSCATTERING SPECTROSCOPY
SCANNING ELECTRON MICROSCOPY
SEGREGATION
SILICON CARBIDES
SUBSTRATES
TRANSMISSION ELECTRON MICROSCOPY
TRAPPING