Novel hard, tough HfAlSiN multilayers, defined by alternating Si bond structure, deposited using modulated high-flux, low-energy ion irradiation of the growing film

Abstract

Hf 1−x−y Al x Si y N (0 ≤ x ≤ 0.14, 0 ≤ y ≤ 0.12) single layer and multilayer films are grown on Si(001) at 250• C using ultra-high vacuum magnetically-unbalanced reactive magnetron sputtering from a single Hf 0.6 Al 0.2 Si 0.2 target in mixed 5%-N 2 /Ar atmospheres at a total pressure of 20 mTorr (2.67 Pa). The composition and nanostructure of Hf 1−x−y Al x Si y N films are controlled by varying the energy E i of the ions incident at the film growth surface while maintaining the ion-to-metal flux ratio constant at eight. Switching E i between 10 and 40 eV allows the growth of Hf 0.78 Al 0.10 Si 0.12 N/Hf 0.78 Al 0.14 Si 0.08 N multilayers with similar layer compositions, but in which the Si bonding state changes from predominantly Si-Si/Si-Hf for films grown with E i = 10 eV, to primarily Si-N with E i = 40 eV. Multilayer hardness values, which vary inversely with bilayer period Λ, range from 20 GPa with Λ = 20 nm to 27 GPa with Λ = 2 nm, while fracture toughness increases directly with Λ. Multilayers with Λ = 10 nm combine relatively high hardness, H ∼ 24 GPa, with good fracture toughness.

Enhanced Mechanical, Thermal and Electrical Properties of High‐Entropy HfMoNbTaTiVWZr Thin Film Metallic Glass and its Nitrides

“…Rather, the strength and density of bonding govern the mechanical properties and thermal stability of TFMG. [36] The strength and ductility of high-entropy-based TFMG can be enhanced with a selection of elements giving rise to high configuration entropy, and high density of strength and bonding between each other, such as the octonary refractory elements chosen in the current work. Using this concept, HfMoNbTaTiVWZr high-entropy TFMG (0% R N ) displayed high hardness and compressive strength and extremely high ductility compared to other TFMG reported thus far.…”

Combined reactive/non-reactive DC magnetron sputtering of high temperature composite AlN–TiB2–TiSi2

“…It is well-known that composition and structure of a film and, consequently, its properties, are controlled via adjusting of deposition parameters of the magnetron such as applied voltage to the target, applied bias on the substrate, substrate temperature, target to substrate distance, working gas pressure and flow rate etc. [3,[16][17][18][19]. Our approach is then based on combining non-reactive/reactive DC magnetron sputtering of a composite target with the aim to synthesize gradient coatings with high N content on the top surface layer.…”