Defect Generation and Gettering during Rapid Thermal

The generation of crystallographic defects induced by metallic impurities diffusing from the back side of silicon wa-fers is observed uring rapid thermal annealing. The type of defect generated depends on both the type and concentration of metal used. Saucer-pits, hillocks, and oxidation induced stacking faults are observed after oxidation in the time range 40-180s. These defects can be annihilated by gettering with a heavily doped P layer diffused into the back side of the wa-fers. The effectiveness ofthis annihilation depends upon the order of the gettering and defect-generating processes. It also depends on the type and concentration of metal used. The detrimental influence of crystallographic defects on the electrical parameters of electron devices is well estab-lished (1). In the conventional (furnace) technology of IC fabrication, one of the main imperfections in single-crystal silicon is due to metallic contamination. Heavy metal im-purities introduce deep levels into the silicon energy band-gap and thus act as effective generation/recombination centers. These impurities have large impact on the semi