Composition, structure, and magnetic properties of SiCxNyFez films produced by the PECVD method from a gas mixture of 1,1,1,3,3,3-hexamethyldisilazane, ferrocene, and helium

Abstract

Composite SiCxNy:Fez films with magnetic properties were obtained by plasma-enhanced chemical vapor deposition from gas mixtures of hexamethyldisilazane, ferrocene, and helium. In the work, the ratio of elements of the initial gas phase was varied at a constant synthesis temperature of 873 K, which made it possible to obtain films that differ significantly in the content of elements, but are similar in structure. Using a complex of modern research methods: infrared spectroscopy, Raman spectroscopy, energy-dispersive X-ray spectroscopy, the relationship between changes in the concentration of elements of the initial gas mixture and changes in the composition of SiCxNy:Fez films was established. The structure of the obtained samples was studied by X-ray photoelectron spectroscopy, extended X-ray absorption fine structure, and X-ray phase analysis. Based on the data obtained, it is assumed that, in the studied range of conditions, the obtained films can be attributed to two different materials. Films containing less than 13% iron consist of an amorphous SiCxNy matrix with inclusions of disordered carbon and iron silicides. Films containing more than 27% iron are composite. The composite includes disordered carbon, iron silicides, and iron carbides. As well as inclusions of silicon nitride, silicon oxide and carbon nitride. It is assumed that the magnetic properties of the films are due to the content of iron silicides and iron carbides in them. Films containing more than 27 at% iron have ferromagnetic properties with a Curie temperature above room temperature.