Elemental distributions and chemical bonding states of oxygen-ion-implanted SiC have been examined using scanning transmission electron microscopy (STEM) equipped with an energy dispersive X-ray spectrometer (EDX) and an electron energy loss spectrometer (EELS). 6H-SiC single crystals with [0001] orientation were implanted with 180 keV oxygen ions at 650 degrees C to fluences of 0.7 x 10(18) and 1.4 x 10(18) cm(2). STEM-EDX/EELS measurements show that the low-dose sample possesses a buried amorphous SiCxOy layer, and oxygen concentration peaks around the center of the buried amorphous layer. On the other hand, a well-defined SiO2 layer including sell-bonded carbon atoms is formed in the high-dose sample, and this amorphous region has a layered structure due to compositional variations of silicon, carbon, and oxygen. A slight chemical disordering induced by implantation is also confirmed to exist in topmost SiC layer.