Defect formation and thermal evolution in H and O co-implanted Si

Abstract

190keV O and 40keV H ions with different fluences were sequentially implanted into crystalline Si at room temperature. The surface damage and defect microstructures after subsequent annealing have been studied by optical microscopy (OM) and cross-sectional transmission electron microscopy (XTEM). The formation of surface damage depends strongly on both the H implant fluence and annealing temperature. After 400°C annealing, surface blistering was first observed on Si co-implanted with O and H ions both at a relative high fluence, while no surface damage was observed on H-only implanted Si. Further annealing led to serious surface damage, such as blistering and localized exfoliation. According to statistics of the size of craters from exfoliated regions, O and H co-implantation could effectively increase the average size of the craters. XTEM observations have revealed that the additional high fluence O implantation could affect the thermal growth of H cavities. The surface damage and defect microstructures induced by O and H co-implantation were tentatively discussed considering the interactions between O, H implants and heavily damaged Si substrate.