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Raman mapping of 4‐MeV C and Si channeling implantation of 6H‐SiC

A 6H‐SiC single crystal implanted in channeling mode by 4‐MeV C+3 and Si+3 ions at various doping levels has been examined by scanning electron microscopy (SEM) and micro‐Raman spectroscopy in order to study the lattice distortions inflicted by the impinging ions. C ions create zones of strongly damaged regions, parallel to the front face of the wafer with width increasing with the amount of doping. As expected, Si has induced considerably more lattice distortions than C, and more than one order of magnitude less doping induces apparently the same effect as C. Despite the large laser spot size compared with the boundaries of the distorted regions, micro‐ Raman data provided results agreeing with the SEM pictures and the Monte Carlo calculations using the SRIM‐2013 software. From the evolution of the crystalline peaks in the Raman spectra obtained across the damaged area, one can conclude that the impinging ions do not accommodate as defects in the lattice but mostly displace the ions breaking the bonds and destroying the long range order. The spatial correlation model that takes into consideration the intensity variation at the laser spot and the anticipated from Monte Carlo calculations for the collision events can reproduce the trend of the strong transversal optical phonon width indicating nanocrystallites of a few nanometers size in the most damaged area.

channeling ; disorder profile ; ion implantation ; phonon confinement ; silicon carbide

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