论文信息 - Investigation of Polycrystalline Nickel Silicide Films as a Gate Material

Investigation of Polycrystalline Nickel Silicide Films as a Gate Material

The work function of polycrystalline nickel silicide film formed by rapid thermal annealing (RTA) has been studied using capacitance-voltage (C-V) measurements and metal-oxide semiconductor (MOS) structures. The effect of sintering temperature on work function has also been studied. Results show that the work function of n + -doped NiSi gate is about 4.6 eV and is stable from 400 to 800°C. For p + -doped NiSi gate, the work function is 5 eV. The gate-substrate leakage current is small and the oxide quality is similar to that in Al-gate MOS capacitors even for oxides as thin as 8 nm. The poly-gate depletion effect (PDE) has also been investigated by quasi-static C-V. Compared with that of poly-Si and poly-Si 1-x Ge x , no PDE is observed in silicide-gate n-MOS device even when the gate is undoped. The results suggest that nickel silicide film may be used as a potential gate material in complementary MOS or thin-film transistor devices.

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