Structural morphology and electronic properties of the Si-Cr interface

Photoemission studies ($12\le \mathrm{hv}\le 135$ eV) of room-temperature formation of the Si-Cr interface show reactive behavior with atomic intermixing and dramatic modifications of the metal-derived $d$ density of states. Self-consistent augmented-spherical-wave calculations of the total and $l$-projected densities of states for the silicides ${\mathrm{Cr}}_3$Si, CrSi, and Cr${\mathrm{Si}}_3$ in simplified cubic lattice structures allow an identification of general trends in the electronic structure upon Si-Cr heteropolar bond formation. These experimental and theoretical results suggest an interface morphology where a Si-rich intermixed phase is present for a depth of $\simeq 10$ monolayers between the Si crystal and the unreacted Cr film. Evidence of Si segregation in the top layers of the Cr film is provided.