Crystallinity and composition of Sc1-x(-y)SixP(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 Sc1-x-y SixPy 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 similar to 450 degrees C and 700 degrees 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. (c) 2024 The Japan Society of Applied Physics