STEM study of interfacial reaction at HfxAl1−xOy/Si interfaces

Physical characterization of hafnium aluminates dielectrics deposited by atomic layer deposition

“…In the case of the films annealed by RTP, although Dai et al [34] reports similar results for Al diffusion, the roughness of the film/substrate interface of the films here studied are lower, i.e, the interface was sharp. This difference could be attributed to the deposition method because in [34] the authors use the pulsed-laser deposition method. Although Hf is inward the silicon at some degree (see Fig.…”

“…According to these results, during the thermal treatment of the films, at least four layers arise due to the interdiffusion of the different chemical elements from the dielectric layer toward the substrate and vice-versa [1,33]. In this sense, Dai et al [34], report that, in Hf x-Al 1-x O y deposited on Si substrate, interlayer between film and silicon is formed by hafnium silicide compound, which is linked to the larger diffusion of Hf toward the substrate. The formation of this interlayer would be accompanied by the formation of a rougher interface [34].…”

“…In this sense, Dai et al [34], report that, in Hf x-Al 1-x O y deposited on Si substrate, interlayer between film and silicon is formed by hafnium silicide compound, which is linked to the larger diffusion of Hf toward the substrate. The formation of this interlayer would be accompanied by the formation of a rougher interface [34]. The results about the thickness layer and roughness of these films (TABLE II) suggest no hafnium silicide formation.…”

“…According to the literature for similar systems [8,13,34], the size of the nanoparticles depends on the Al concentration within the film. Lower concentrations of Al yields bigger nanoparticles, while high concentration of this element leads to the formation small nanoparticles with complex geometry with dimensions within the same order here obtained (≈ 6 nm) [8,34]. On the other side, in addition to the Al concentration dependence of the nanoparticle formation, our results highlight that the phase separation depends on the annealing method as well as of the composition of the annealing atmosphere.…”

Study on Composition Distribution and Ferromagnetism of Monodisperse FePt Nanoparticles

“…We carried out atomic compositional analysis of the nanoparticles by examining the composition of individual particles. It’s known that in the high-angle annular dark field (HAADF) image, the elements with higher atomic number will have brighter contrast compared to the light elements with lower atomic number [ 15 ]. Therefore, it’s reasonable to assume that for the isolated FePt NPs, the brighter spots are corresponding to the Pt-rich particles while the darker spots are the Fe-rich ones, since Fe has a significantly lower atomic number than Pt.…”