High-dose chromium implantation resulted in complex changes in the structure, chemistry, and oxidation behaviour of beta-type single-crystal silicon carbide. Detailed analytical studies indicated that, in addition to the primary process of surface doping, chromium implantation of silicon carbide to 3.90 x 10(17) ions cm(-2) at 200 keV was accompanied by many secondary processes such as surface sputtering, lattice damaging, and silicon depletion/carbon enrichment in the implanted region. These changes resulted in accelerated oxidation of the implanted samples by a factor of 1.14 as compared with the unimplanted crystals in 1 atm of flowing oxygen at 1100 degrees C. The oxidation layer exhibited interesting structural and compositional inhomogeneity which could be explained based upon chromium mobility variation in the implanted region. The presence of densely populated chromium oxide precipitates in the outer region of the oxidation layer played a significant role in keeping the degree of oxidation acceleration low under the detrimental influence of lattice damages and silicon deletion/carbon enrichment. It was concluded that the potential of chromium implantation to improve the oxidation resistance of silicon carbide can be realized only when the implantation-induced secondary effects are suppressed.