A high-performance ceramic material widely used in thin-film deposition technology.

It is mainly used for the preparation of functional thin films by magnetron sputtering (PVD), pulsed laser deposition (PLD), and other methods.

It has excellent insulation, corrosion resistance, mechanical strength, and optical properties,and is an important target material in fields such as semiconductors, optical coatings, wear-resistant coatings, and new energy.

1. Characteristics

１）High insulation and dielectric

・Dielectric constant (ε) suitable for high-frequency electronic devices: ~9-10 (1 MHz)

・Strength of breakdown field: >10MV/cm and is a good quality insulating layer material.

２）Excellent chemical stability

・Acid-alkali corrosion resistance (except HF), oxidation resistance, suitable for harsh environments (chemical plant coatings, etc.).

・Good high-temperature stability (melting point ~ 272°C), can be used for high-temperature protective layers.

３）High hardness and wear resistance

・Mohs hardness ~ 9 (second to diamond), suitable for wear-resistant coatings on tools and molds (e.g., Al₂O₃/TiN composite).

４）Optical transparency

・High light transmittance in the ultraviolet (UV) to infrared (IR) band (200 nm to 5 μm), suitable for optical coatings.

５）Biocompatibility

・Non-toxic and non-irritant, which can be used for surface modification of medical devices such as artificial joints and dental implants.

６）High purity and density

・Semiconductor grade Al₂O₃ target purity ≧99.99% (4 N), some application requirements ≧99.999% (5 N).

・Hot Isostatic Pressurization (HIP) sintering is used to achieve densities >99% and to reduce particle scattering during sputtering.

2. Main applications

１）Semiconductors and electronic devices

・Gate dielectric layer: Insulating layer for power devices such as MOSFETs, GaN HEMTs.

・Passivation layer: Protects chip surfaces and prevents moisture and ion contamination (e.g. LED packages).

２）Optical coatings

・Transparent film (AR coating)

・Infrared window materials

３）Wear Resistant and Protective Coatings

・Cutting tool coatings (e.g., Al₂O₃/TiC)

・Aero engine blade coatings

４）New energy and batteries

・Separator coating for lithium-ion batteries: To improve the thermal stability and electrolyte wettability of separators.

・Solid electrolytes: Used in all-solid-state batteries (e.g., Li₇La₃Zr₂O12/Al₂O₃ alloy electrolytes).

５）Medical applications

・Artificial bones and dental implants : To enhance biocompatibility and wear resistance.

・Medical sensor insulating layer : Implant blood glucose monitoring electrodes, etc.

６）Other newly emerging fields

・Flexible electronic encapsulation: As water barrier oxygen barrier layer (instead of SiN 8339).

・Quantum dot display : Insulating layer for QD-LEDs.