Laser spike annealing for nickel silicide formation

Recent work has shown that laser annealing may have advantages over conventional RTP for nickel silicidation formation, such as lower leakage and better device performance. However, there are a number of requirements that must be met by any millisecond annealing tool to successfully bring this process to a high volume manufacturing environment. Ultratech's new low-temperature LSA system is designed to meet these requirements for middle-of-line processes such as nickel silicidation. Specifically, this system meets the requirements of within-die temperature uniformity, layout-independent processing, and closed-loop temperature control. Supporting data is presented for each of these requirements. Characterization data on blanket NiPt wafers is also presented which shows that a large step size can be used during the rastoring of the laser beam over across the wafer, enabling a production-worthy throughput of 70wph to be achieved by LSA.