Effect of a Mo interlayer on the electrical properties of Ni-silicided n⁺/p diode and n⁺poly-Si gate electrode

We have investigated the effect of a Mo interlayer on the electrical properties of Ni-silicided n+ p diodes and n+ poly-Si gate electrodes. It is shown that the use of the Mo interlayer results in reduction of the reverse leakage current of the Ni-silicided n+ p diodes. It is also shown that the interlayer effectively serves as a barrier to the in-diffusion of interconnection Al, leading to the formation of the uniform silicide layer. It is further shown that the Ni-silicided poly-Si gate electrodes with the interlayers produce similar equivalent oxide thickness and a positive shift of flatband voltage (VFB), compared to the samples without the interlayers. Secondary ion mass spectroscopy results show that Ni is segregated at the poly- Si SiO2 interface and the Mo interlayer affects the redistribution of phosphorus.