Formation and properties of nickel silicides in the Ni/Mo/Ni/Si(100) thin-film system

Silicides are crucial for reducing contact resistance in microelectronics, and controlling their formation and stability remains a key challenge for improving device performance. This study investigates the structural and electrical properties of nickel silicides in the Ni/Mo/Ni/Si thin-film system, focusing on the role of a molybdenum (Mo) interlayer as a diffusion barrier. Samples were prepared via cathodic sputtering and characterized using X-ray diffraction, Raman spectroscopy, and four-point resistivity measurements. The results reveal that the Mo interlayer delays the formation of NiSi to 400 degrees C and limits its agglomeration, ensuring phase stability up to 600 degrees C. The complete transformation to NiSi2 occurs only at 800 degrees C, highlighting the interlayer's effectiveness in suppressing undesired phase transitions. Furthermore, the Mo interlayer reduces electrical resistivity by extending the stability of the low-resistivity NiSi phase. These findings offer valuable insights for optimizing silicide properties and thermal stability in microelectronic applications, paving the way for more efficient and reliable devices.