Damage accumulation and defect relaxation in 4H-SiC
- Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352 (United States)
A nonlinear dependence of damage disorder on dose is observed for both Si and C sublattices in 4H-SiC under 2 MeV Au irradiation at 165 K. The relative disorder observed along the <4403> direction is much higher than that along the <0001> direction. Molecular dynamics (MD) simulations demonstrate that most interstitial configurations are formed on the Si-C dimer rows that are parallel to the <0001> direction. As a result, these interstitials are shielded by the Si and C atoms on the lattice sites, which significantly reduces the contribution of these interstitials to the backscattering/reaction yield along the <0001> direction. During isochronal annealing below room temperature, the relative disorder decreases along the <0001> direction, as expected; however, the disorder is stable on the Si sublattice and increases slightly on the C sublattice when measured along the <4403> direction due to relaxation of some metastable defects to lower energy configurations. As the annealing temperature increases, similar recovery behavior on both Si and C sublattices along the <0001> direction indicates coupling of Si and C recovery processes; however, slightly higher recovery temperatures on the C sublattice along the <4403> direction suggests some decoupling of the Si and C recovery processes. Based on the structures and energetics of defects from MD simulations, new insights into defect configurations and relaxation processes are described.
- OSTI ID:
- 20664874
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 70, Issue 12; Other Information: DOI: 10.1103/PhysRevB.70.125203; (c) 2004 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANNEALING
BACKSCATTERING
COUPLING
DAMAGE
DECOUPLING
DEFECTS
GOLD
INTERSTITIALS
MEV RANGE 01-10
MOLECULAR DYNAMICS METHOD
RADIATION EFFECTS
RELAXATION
SEMICONDUCTOR MATERIALS
SILICON CARBIDES
SIMULATION
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K