Effects of carbon pre-silicidation implant into Si substrate on NiSi

• The effects of carbon pre-silicidation implant in Si substrate on NiSi were investigated.
• NiSi films with and without C were checked by versatile characterizations.
• The presence of C leads to improved thermal stability of NiSi at the expense of increased Rsh.
• C at grain boundaries and at NiSi/Si interface accounts for improved thermal stability of NiSi.
• The dose of carbon pre-silicidation implant also plays a key role in the formation of NiSi.

In this work, the effects of carbon pre-silicidation implant into Si(1 0 0) substrate on NiSi were investigated. NiSi films with carbon pre-silicidation implant to different doses were characterized by means of sheet resistance measurements, X-ray diffraction, scanning electron microscopy (SEM), planar view transmission electron microscopy (TEM) and second ion mass spectroscopy (SIMS). The presence of C is found to indeed significantly improve the thermal stability of NiSi as well as tends to change the preferred orientations of polycrystalline NiSi. The homogeneously distributed C at NiSi grain boundaries and C peak at NiSi/Si interface is ascribed to the improved thermal stability of NiSi. More importantly, the dose of carbon pre-silicidation implant also plays a key role in the formation of NiSi, which is suggested not to exceed a critical value about 5 × 1015 cm−2 in practical application in accordance with the results achieved in this work.

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