We have successfully fabricated nickel silicide metal-oxide-semiconductor (MOS) capacitors at 280 C by metal chloride reduction chemical vapor deposition (MCR-CVD). In this process, we first prepared polycrystalline silicon (poly-Si)/SiO 2overcoated Si wafers and exposed the wafers to Cl plasma containing NiCl for 40 min with a substrate temperature of 280 C. 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.

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We have successfully fabricated nickel silicide-metal gate MOS capacitors at a low temperature of 280 C by treating poly-Si stacked SiO 2 /Si substrates with a Cl plasma containing NiCl. We have confirmed atomically sharp NiSi/oxide interfaces after the present process where any interface segregation can not be observed by cross-sectional TEM measurements. The present process allows a control of Ni concentration in the gate metal film and the work function in the gate metal is adjustable in the range from 4.3 to 4.9 eV, which is suitable for the Si CMOS process.

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