Effect of MeV implantation gettering for improvement of device characteristics

This paper reports on the effect of MeV implantation for Fe gettering and the improvement of device characteristics. MeV B or B and O co-implantation were effective for eliminating the failure of 8 nm gate-oxide on CZ wafers. Defects due to MeV implantation could not be detected in the device active region. Only A-mode failure was observed in 4 nm gate-oxide fabricated on MeV implanted CZ. The reason of the failure is not the lack of gettering ability but Fe-oxide formation. Low Fe contamination below 1/spl times/10/sup 10/ cm/sup -2/ can be obtained on MeV implanted CZ by RTA in oxygen-free ambient before gate-oxidation.