Influence of a small amount of oxygen during rapid thermal processing on cobalt salicide at 65 nm gate length

The main issue in cobalt salicide process is the difficulty of obtaining low sheet resistances at narrow line width. In the present work, we have studied the relationship between oxygen concentration in rapid thermal processing (RTP) chamber and the electrical properties of cobalt silicide in CMOS devices. It is found that failures of CoSi/sub 2//poly-Si gate electrodes with 62 nm gate length are induced by a small amount of oxygen (25 ppm) in the chamber of RTP system.