STRUCTURAL AND ELECTRONIC PROPERTY EVOLUTION OF NICKEL AND NICKEL SILICIDE THIN-FILMS ON SI(100) FROM MULTICORE X-RAY-ABSORPTION FINE-STRUCTURE STUDIES

We report an x-ray-absorption fine-structures (XAFS) investigation of a series of nickel and nickel silicide thin films prepared by magnetro n sputtering nickel on Si(100) substrates and sequential annealing pro cedures. XAFS at the Ni K edge, Si K edge, and Si L-3.2 edge have been used to monitor the structure and bonding systematics at different st ages of the silicidation process. It is found that the as-deposited fi lm exhibits noticeable intermixing at the Ni-Si interface at room temp erature, leading to the formation of a Ni-rich silicide in the vicinit y of the interface; as the annealing temperature increases, predominan tly NiSi and NiSi2 phases are sequentially formed. It is also shown th at Si L-3.2-edge studies using total electron yield and fluorescence y ield are ideally suited for noninvasive characterization of silicide t hin films. [S0163-1829(98)01115-1].