MEV-ION-INDUCED DAMAGE IN SI AND ITS ANNEALING

The interactions between buried defects and impurities formed by MeV ion implantation in Si have been investigated from the following aspects: First, the interactions between the O atoms in CZ Si and the defects introduced during annealing after implantation with various ions, such as B, C, F, Si, P, Ge and As, are discussed by clarifying the amount, nature, morphology and depth distribution of the generated defects. Generally, oxygen atoms are gettered in two different regions of implanted layers. A shallow O peak appears in regions near the surface (between 0.5 and 1.5-mu-m deep), where no visible defect band exists. A deep peak of O is observed at locations where severe defects exist. These results are explained by considering ion mass, mismatch stress and point defects generated along individual ion tracks. Second, the effect of additional C and F implantation on density reduction and on changes in the configuration of defects formed by individual P and B implantation is reported. Under optimum implantation conditions, an effective suppression of elongated defect formation is observed after annealing at temperatures above 800-degrees-C. The results are discussed on the basis of interactions between implantation-induced interstitials (which are responsible for secondary defect formation) and implanted C and F atoms.