We investigated Ni 1−x Pt x Si ͑x = 0.05-0.33͒ as a metal gate electrode for p-metal oxide semiconductor field effect transistors ͑MOSFETs͒. Our results showed that, with a proper atomic composition of Ni 1−x Pt x Si, the work function of the gate electrode can be tuned from ϳ4.59 eV ͑for NiSi͒ to ϳ5.21 eV ͑for Ni 0.67 Pt 0.33 Si͒. Negligible variations in both the extracted flatband voltages and gate oxide thicknesses with processing temperature ͑up to 900°C͒ demonstrated the excellent thermal stability of the Ni 0.67 Pt 0.33 Si-SiO 2 gate stacks. High-resolution transmission electron microscopy also showed no evidence of degradation at the Ni 0.67 Pt 0.33 Si-SiO 2 interface and the formation Ni and/or Pt precipitates at/or beneath the SiO 2 -Si interface.The introduction of metal gate electrodes in nanoscale complementary metal-oxide-semiconductor ͑CMOS͒ devices is imperative to overcome problems associated with poly-Si gate such as polydepletion effects and boron penetration. 1 However, to achieve optimal operation of high performance bulk CMOS devices, the required gate work functions for n-and p-channel transistors should be within 0.2 eV of the conduction and valence bandedges of Si, respectively. 2 While tailoring the work functions of poly-Si is achieved readily by dopant incorporation, this may not be true for a metal gate electrode; hence the achievement of appropriate metal gate work functions for nanoscale CMOS devices is crucial to realizing dual metal gate CMOS devices. Recently, fully silicided NiSi was shown to be an attractive alternative to elemental metals for metal gate electrode applications. [3][4][5][6][7][8] It was demonstrated that fully silicided NiSi gates effectively reduce poly-depletion effects and have lower sheet resistance with a work function that can be tuned by the implantation of different dopants ͑e.g., As, P, B, and BF 2 ͒ at varying implant doses into a silicon film before full silicidation. Cabral and co-workers have also recently shown that the work function of the fully silicided NiSi gate can be tuned by the full silicidation of poly-Si or Al-doped poly-Si by a Ni͑Pt͒ alloy, increasing the work function value of the fully silicided NiSi gate to 4.76 and 4.96 eV, respectively. 9 In this letter, we investigated the dependence of Ni͑Pt͒Si gate work function on the Pt content and demonstrated that a continuous and tunable work function from ϳ4.59 to ϳ5.21 eV could be achieved. The effects of Pt incorporation on the Ni͑Pt͒Si-SiO 2 and SiO 2 -Si interface integrity were also examined, which revealed no evidence of degradation. Negligible variations in the extracted flatband voltages and gate oxide thickness from 400 to 900°C rapid thermal annealing also demonstrate the excellent thermal stability of the Ni 0.67 Pt 0.33 Si-SiO 2 interface.Ni 1−x Pt x Si-gated MOS capacitors with different Pt content ͑x = 0.05, 0.10, 0.25, and 0.33, calibrated by Rutherford backscattering for x = 0.05 and 0.10 with x = 0.25 and 0.33 estimated by the ratios of the original Ni and Pt layer thickn...

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