The effect of ramp rate: Short process time and partial reactions on cobalt and nickel silicide formation

New approaches to form cobalt and nickel silicide have been investigated using fast ramp rate, short thermal budget, and partial reaction (when the anneal is stopped before all the Co or Ni layer is transformed into the silicide). All anneals were possible using the Levitor system. In this system the heating does not depend on the wafer optical properties, or pattern on the wafer. Therefore it enables uniform heat -up even at very low temperature. This study has demonstrated that both fast ramp rate and short thermal budget do not deteriorate the silicide properties (SEM, AFM, XRD and TOFFSIMS). For very low temperature processes (Ni-silicide), it has been observed that using short anneal time reduce the reverse linewidth effect.