Counting the Applications of Alumina Ceramics as Semiconductor Equipment Components

In recent years, national policy adjustments have accelerated the development of the semiconductor industry, leading to rapid growth in scale and advancements in manufacturing equipment. As semiconductor fabrication processes become increasingly precise and complex, advanced ceramics have gained prominence due to their exceptional properties, including high hardness, high elastic modulus, excellent wear resistance, insulating capabilities, corrosion resistance, and low thermal expansion.

These characteristics make ceramics essential materials for components in equipment such as wafer polishing machines, thermal treatment systems for epitaxy, oxidation, and diffusion, lithography machines, deposition equipment, etching tools, and ion implanters. Among the available materials, alumina (Al₂O₃) has emerged as the most popular precision ceramic material, finding extensive application in semiconductor manufacturing.

Etching is a critical step in semiconductor, microelectronics, and micro-nano fabrication. During the etching process in etching machines and PECVD equipment, plasma interactions can cause significant wear and damage to the surface of machine components. These interactions lead to:

• Corrosion: Shortened component lifespan and reduced equipment performance.

• Contamination: Reaction byproducts volatilize and detach, creating particulates that compromise the cleanliness of the process chamber.

High-purity alumina (Al₂O₃) coatings are commonly employed as protective materials for etching chambers and their components:

• Traditional Chamber Materials:

Early etching chambers used aluminum alloys, which were prone to metal particle contamination. To address this, dense anodized alumina layers were applied to the alloy surfaces, improving corrosion resistance. However, these anodized layers often developed microcracks due to impurities in the alloy, limiting their effectiveness.

• Advances in High-Purity Alumina Coatings:

High-purity Al₂O₃ coatings have since become standard in etching chambers. However, differences in thermal expansion coefficients between the coating and substrate can lead to cracking, which reduces corrosion resistance.

Dense, high-purity bulk alumina ceramics offer superior plasma resistance compared to coatings. These ceramics typically have a purity exceeding 99%, with controlled metal oxide impurities (e.g., MgO, CaO, SiO₂) within 0.05%–0.8% to enhance plasma resistance while maintaining sintering performance.

Semiconductor devices demand nearly perfect wafers to avoid detrimental electrical and mechanical defects. During wafer processing, which includes shaping, slicing, grinding, and cleaning, wafers must be securely positioned and stabilized. This is achieved using ceramic vacuum chucks.

• Material Properties and Structure:

Vacuum chucks are typically made from alumina or silicon carbide. These ceramics feature porous or hollow structures achieved through high-temperature sintering. A vacuum effect is generated by applying negative pressure to the porous ceramic matrix, securely fixing wafers, glass substrates, or other workpieces.

• Applications of Ceramic Vacuum Chucks:

• Fixtures for wafer thinning processes such as grinding, polishing, and chemical mechanical planarization (CMP).

• Mounts for measurement and inspection devices.

• Clamping tools for processing thin films, sheets, and metal substrates.

The production of these integrated hollow-structure ceramics requires advanced manufacturing techniques, reflecting their critical role in the precision and reliability of semiconductor equipment.

As the semiconductor industry advances, the demand for precision materials like alumina ceramics continues to grow. From enhancing plasma resistance in etching chambers to providing stability in wafer processing, alumina ceramics are indispensable for achieving the precision and performance required in modern semiconductor fabrication. With ongoing research and technological innovation, the potential of alumina ceramics in driving the future of semiconductor manufacturing is boundless.