Dynamic annealing in ion implanted SiC : Flux versus temperature dependence

• A strong influence of ion implantation flux on the accumulation of radiation damage, the so-called dose rate effect, is observed and systematically studied in SiC. 100 keV Si+ ions were implanted into bulk 4H-SiC wafers using different ion fluxes (1.9x10(10)-4.9x10(13) ions/cm(2) s) and keeping the implantation dose constant at 5x10(14) Si+/cm(2). The implants were performed both at room and elevated temperatures, up to 220 degreesC. Rutherford backscattering spectrometry in the channelling mode using 2 MeV He+ ions was employed to measure ion implantation damage profiles in the samples. For the flux interval used the most, pronounced dynamic annealing effect was detected at 80-160degreesC, having an activation energy of 1.3 eV. For example, at 100degreesC the amount of disordered Si atoms at the projected ion range is reduced by a factor of 4 by decreasing the ion flux from 4.9x10(13) to 1.9x10(10) ions/cm(2) s. The results are discussed in terms of migration and annihilation of intrinsic type defects for both the Si- and C-sublattices. In addition, two regions for the damage accumulation - at the surface and at the damage peak for 100 keV Si+ ions - are observed.

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damage accumulation

point-defects

dose-rate

gaas

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