Elaboration and Physical Characterization of CoxCr100-x Thin Films

Abstract

In this work, we have studied the electrical and structural properties of CoxCr100-x thin films thermally evaporated onto Si(111) substrates. The atomic compositions evaluated from X-Ray Fluorescence (XRF) analysis are found to range from 12.2 to 15.0 at.% for Chromium. The film thickness varies between 559.1 nm and 706.3 nm. The structural properties have been determined by the X-ray diffractometry technique (XRD). X-Ray diffraction spectra present (111), (200), and (220) Bragg peaks for all the samples deposited onto Si(111). The preferential orientation for all samples is <200> with an FCC-phase. The lattice parameter and the compressive microstrain decrease slightly with the atomic composition. The root mean square roughness (Rms) varies between 267 and 453 nm. The electrical properties have been analysed by means of a four-point probe apparatus. The electrical resistivity increases with the chromium content. The resistivity, Rms, and grain size evolutions are studied versus chromium content, and they have been found to present a strong correlation. The resistivity values vary between 0.246 and 0.297 Ω·cm for the CoxCr100-x /Si(111) thin films. The films exhibit a nanocrystalline structure, and their microstructural evolution is perfectly described by Zone 1 of the Thornton model.