Optimization Of Nickel Thickness Uniformity And Its Influence On Device Electrical Properties

As the feature size of device, which is represented by Gate size, scaling down, Self-aligned nickel silicide (or Ni-Salicide) is more and more widely used in Super-Large Scale Integration (or SLSI) manufacturing to reduce the contact resistance of Source, Drain, Gate and interconnectors. The thickness of nickel (Ni) plays a key role during the salicidation process. It could be resulting in a critical drift of device electrical properties even if a minor excursion of Ni thickness. Therefore, it has become extremely important to ensure the within-wafer Ni thickness uniformity.In this paper, the correlation between Ni thickness within-wafer uniformity and various manufacturing parameters has been investigated for seeking the parameter which can be used for optimizing Ni thickness within-wafer uniformity during manufacturing. And the influence of Ni thickness within-wafer uniformity on Device electrical properties has been investigated by adjusting this parameter. The parameters involved in this paper were DC Power, Gas Flow, Process Spacing, Magnet Spacing and Magnet Speed. The thickness of nickel film was 11nm (110A), which was deposited by Endura PVD platform of Applied Materials (AMAT) using Physical Vapor Deposition (PVD) sputtering process. Ni-Salicide, which comprised of NiSi only, was formed using two steps RTA anneal salicidation process.The finding of this paper showed that the Device Electrical properties can be optimized by adjusting Process Spacing, which controls within-wafer Ni thickness uniformity, during industrial manufacturing.