Characterization of Nickel Silicides Produced by Millisecond Anneals

Nickel silicides serve as the source, drain, and gate contact material in many advanced complementary metal oxide semiconductor (CMOS) logic applications. Nickel has demonstrated numerous advantages over Cobalt and Titanium silicides of earlier technology nodes. Traditionally, these silicides have been formed by Rapid Thermal Processing (RTP) techniques. Two separate RTP anneals are typically used to form the silicides. In this paper, we explore the formation and film characteristics of nickel silicides produced by millisecond anneals. An overview is first provided of the nickel silicide resistivities as a function of RTP anneal temperature. When plotted, this data provides the transformation curves for the RTP Soak and Spike anneals of thin nickel films. A method is described for estimating the nickel silicide activation energy using these transformation curves and, subsequently, a calculation of the requisite laser power to produce a nickel silicide of comparable resistivity. Film characteristics and morphology of the resultant nickel silicides are evaluated by Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD) analysis techniques.