Crystallinity and composition of Sc1−x(−y)Si x (P y ) silicides in annealed TiN/Sc/Si:P stacks for advanced contact applications

Abstract Sc-based contacts to Si:P have shown great potential for NMOS devices. However, the promising properties of this material system are not yet fully understood. This work provides new insights into the crystallinity and composition of annealed TiN/Sc/Si:P stacks. After silicidation, two distinct phases are evidenced, with orthorhombic ScSi lying atop a thin Sc 1− x − y Si x P y interfacial layer that shares a commensurate interface with the underlaid Si:P, hypothetically resulting in a low interface defectivity. The formed ScSi phase is observed to be thermally stable between ∼450 °C and 700 °C, which is suitable for most device applications. The impact of additional thermal budgets within this temperature range is investigated, revealing potential origins for thermally induced degradation of the contact properties.