The development of advanced machining techniques requires high-performance tool coatings. To improve the wear resistance and cutting performance of AlTiN coatings, a structure optimization strategy involving bias control and a nano-multilayer architecture strategy is presented. The investigated AlTiN coatings were deposited by cathodic arc evaporation and studied with regard to phase structure, hardness, adhesion, and tribological properties by a combination of X-ray diffraction, nanoindentation, scratch, and ball-on-disk friction tests. A high bias potential (up to −120 V) with enhanced adatom mobility suppressed the formation of the wurtzite structure AlN in AlTiN. In addition, the epitaxial growth of Al_0.67Ti_0.33N on Al_0.5Ti_0.5N in the AlTiN nano-multilayer could also promote the single-phase structure. The hardness of AlTiN-based coatings with a dominated cubic structure was 3–4 GPa higher than conventional ones. In addition, the interlayer interfaces in the Al_0.67Ti_0.33N/Al_0.5Ti_0.5N multilayer could deflect the cracks and thus improve the fracture toughness. As a consequence, the Al_0.67Ti_0.33N/Al_0.5Ti_0.5N multilayer with enhanced mechanical properties obtained the lowest wear rate of 1.1 × 10⁻⁵ mm³/N·m and the longest cutting lifetime of 25 min during dry turning the SUS304 stainless steel.

By integrating cathodic arc evaporation (CAE) with magnetron sputtering (MS) or high-power impulse magnetron sputtering (HiPIMS), hard coatings with diverse multicomponent compositions can be fabricated. Depending on the deposition conditions, the coatings with nano-composite or nano-multilayered microstructures are produced. During the mixing deposition conditions, nano-composite coatings are fabricated, which can be tailored to possess combining properties of super hardness, low friction coefficient, and excellent thermal/chemical stability. For the deposition with larger rotating periods, layer-by-layer deposition was observed. By the nano-multilayered coating design, superior mechanical properties (hardness ≥ 35 GPa), modulated residual stresses, and enhanced high-temperature properties can be obtained. In addition, lubricious elements, low friction (friction coefficient < 0.4), and low wear (<10⁻⁵ mm³/N∙m) both at ambient temperature and high temperature can be realized. Among these coatings, some have been specifically designed to achieve outstanding cutting performance in high-speed cutting applications. Several nitride and oxide hard coatings, such as AlTiN, TiAlN/TiSiN, AlCrN/Cu, and AlCrO, were deposited using a hybrid industrial physical vapor deposition (PVD) coating system. The microstructure, mechanical properties, and cutting performance of these coatings will be discussed.

Yttrium oxide (Y₂O₃) films have been widely used as protective layers in plasma etching equipment, but achieving stoichiometric films with high deposition rates remains a challenge. In this study, Y₂O₃ films were fabricated by a medium-frequency reactive magnetron sputtering (MF-RMS) technique. The oxygen flow and target control voltage were regulated through a closed-loop feedback control system, which effectively solved the problem. The microstructure, mechanical, optical, and plasma etching properties were systematically investigated. The results showed that near-stoichiometric films can achieve a relatively high deposition rate. Increasing the deposition temperature induced a structural transition in the Y₂O₃ film from a predominantly cubic phase to a mixture of cubic and monoclinic phases. For Y₂O₃ films deposited at room temperature, increasing the bias voltage increased the deposition rate but reduced hardness and elastic modulus. The Y₂O₃ film deposited at 300 °C in the near-metallic mode exhibited the highest hardness and elastic modulus, reaching 13.3 GPa and 222.0 GPa, respectively. All Y₂O₃ films exhibited excellent transmittance and resistance to plasma etching. This study provides an effective protective strategy for semiconductor etching chambers.