Effects of carbon pre-germanidation implant into Ge on the thermal stability of NiGe films

• The NiGe films with various C doses was investigated systematically.
• The incorporation of C effectively improves the thermal stability of NiGe.
• The presence of C also changes the preferred orientations of NiGe.
• C distributes homogeneously within NiGe and segregates at NiGe/Ge interface.
• This distribution of C accounts for the improved thermal stability of NiGe.

In this work, the effects of carbon pre-germanidation implant into Ge on the properties of NiGe films were systematically investigated. NiGe films with carbon pre-germanidation implant to doses varying from 0 to 6 × 1015 cm−2 were characterized by means of sheet resistance measurement, X-ray diffraction (XRD), scanning electron microscopy (SEM), cross-sectional transmission electron microscope (X-TEM) and secondary ion mass spectroscopy (SIMS). The presence of C atoms is proved to significantly enhance the thermal stability of NiGe by about 100 °C as well as to change the preferred orientations of polycrystalline NiGe. The homogenous redistribution of C atoms within NiGe films and the segregation of C atoms at the NiGe/Ge interface is responsible for the improved thermal stability of NiGe films.

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