Low-Temperature Fabrication of Nickel Silicide Metal Oxide Semiconductor Capacitors at 280℃ by Metal Chloride Reduction Chemical Vapor Deposition

摘要

We have successfully fabricated nickel silicide metal-oxide-semiconductor (MOS) capacitors at 280℃ by metal chloride reduction chemical vapor deposition (MCR-CVD). In this process, we first prepared polycrystalline silicon (poly-Si)/SiO_2-overcoated Si wafers and exposed the wafers to Cl plasma containing NiCl for 40 min with a substrate temperature of 280℃. During this process, the top layer of poly-Si is changed to a nickel silicide film with the Ni concentration at approximately 50%. Depth-resolved X-ray photoelectron spectroscopy (XPS) showed a uniform profile of the top film and a sharp interface on the SiO_2 surface at such Ni concentration. We have also obtained capacitance-voltage (C-V) characteristics using a MOS capacitor from the processed wafer. We demonstrate the possibility and applicability of MCR-CVD in the near room temperature (RT) fabrication of metal gate MOS capacitors.