XPS calibration study of thin‐film nickel silicides

Abstract

produced by annealing of sputtered thin films. The in situ XPS study focuses on both the core level peaks and Auger peaks. The peak positions, shapes, satellites as well as Auger parameters are compared for different silicides. The factors that influence the Ni core level peak shifts are discussed. The Ni 2p 3/2 peak shape and satellites are correlated with the valence band structure. The effect of argon ion etching on surface composition and chemical states is also investigated.

Contact Formation on Silicon Carbide by Use of Nickel and Tantalum in a Materials Science Point of View

“…The effect of preferential sputtering decreases with increasing ion beam energy . After the prolonged ion etching, the Ni level becomes constant and reaches saturation level (Cao et al, 2009). The smallest preferential sputtering of Si occurs for Ni 3 Si, whereas it is most evident for NiSi 2 .…”

“…Surface silicides were prepared by means of thin film solid-state reactions controlling the heating procedure in vacuum and the right sample preparation. (Cao et al, 2009) XPS (X-ray photoelectron spectroscopy) can be used as a fingerprint for correct phase identification at the surface. The XPS core level spectra of Ni 2p 3/2 in different silicides are shown in Fig.…”

“…Depth profiling by argon ion etching is a widespread method in studies of film structure and composition. Argon ion etching is a collisional process involving particle-solid (Cao et al, 2009) derived from successive ion etchings and analysis of the Si 2p and Ni 2p 3/2 levels in XPS. During the initial time period of argon ion etching, the surface composition for all the Ni silicides changes with increasing etching time; preferential sputtering of Si occurs, resulting in enrichment of the heavier element Ni.…”

Defect-Free Erbium Silicide Formation Using an Ultrathin Ni Interlayer

“…When the annealing temperature is low (400°C), the average position of the Si 2p peak is located at a binding energy of ∼99.5 eV, which is nearly the same as that of the Si−Si bond from the substrate (separately measured from a reference Si wafer), as shown in Figure 6b. The binding energy of Ni−Si formed at a low temperature is reported to be close to that of Si−Si, 18 and also the reaction kinetics between Ni and Si prefers the formation of nickel silicide at this temperature. 11,12 Therefore, although there is a large contribution of the overlapping Si 2p signal originating from the underlying Si substrate, the Ni interlayer is expected to be converted to a nickel silicide phase.…”

“…The spectra reflecting the chemical information on the interfacial region were selected by considering the depth profiling data of the Si 2p core level; all spectra in Figure 6 were obtained immediately prior to the intensity saturation of the Si substrate peak. A Ni 2p 3/2 peak appears at a higher binding energy (∼853.9 eV) than that of metallic Ni (∼852.7 eV) 17,18 for the sample annealed at 400°C, as shown in Figure 6a. This implies a possible reaction between the interface Ni and the Si to form a nickel silicide phase, as expected given the J−V characteristics.…”