How does white corundum micropowder achieve nanoscale ultra-precision polishing of semiconductor wafers and optical glass?
Publish Time: 2025-10-08
In high-end manufacturing, surface quality directly determines product performance and lifespan. Whether it's the flatness of a semiconductor wafer's circuit layer or the consistent light transmission of an optical lens, surface roughness must reach nanometer or even sub-nanometer levels. White corundum micropowder, with its high purity, high hardness, controllable particle size, and chemical stability, is a key material for achieving this ultra-precision polishing, playing an irreplaceable role in industries such as semiconductors, optics, and precision instruments.
1. High Purity and High Hardness Lay the Foundation for Precision Polishing
White corundum is produced from industrial alumina smelted at high temperatures in an electric arc furnace. Its aluminum oxide content is typically over 99%, with extremely low levels of impurities such as iron, silicon, and sodium. This high purity prevents surface contamination or scratches caused by embedded impurities or chemical reactions during the polishing process. Furthermore, with a Mohs hardness of 9.0, second only to diamond and silicon carbide, white corundum effectively removes microscopic surface protrusions from hard materials, achieving efficient cutting. This combination of rigidity and flexibility—sufficient hardness for material removal while controlled particle size prevents deep damage—makes it an ideal abrasive for nano-level polishing.
2. Precise Particle Size Grading Achieves Nanoscale Surface Control
White corundum micropowder used for ultra-precision polishing typically undergoes multi-stage airflow classification and wet sedimentation, with some high-end applications even utilizing submicron grades. Such fine, evenly distributed particles form a stable suspension in the polishing slurry, enabling uniform and minimal material removal from wafers or optical glass surfaces. Each particle acts like a miniature "carver," driven by the polishing pad and repeatedly applying controlled force to the surface, gradually eliminating scratches, pits, and stress layers left by previous steps, ultimately achieving a mirror-like finish.
In chemical-mechanical polishing, white corundum micropowder not only performs a mechanical abrasive action but also works synergistically with the chemical components of the polishing slurry. For example, during silicon wafer polishing, alkaline polishing fluid softens the surface oxide layer, while white corundum micropowder efficiently removes the softened layer, achieving a "chemical softening-mechanical removal" cycle. Because white corundum is chemically stable and does not react violently with most acids and bases, it introduces no additional byproducts, ensuring a clean and controllable polishing process. It is particularly suitable for semiconductor manufacturing environments, where cleanliness is paramount.
4. Low defect rate ensures high yield of high-end devices
In semiconductor manufacturing, even a single nanometer-sized particle residue or micro-scratch can cause a chip short circuit or performance failure. White corundum micropowder undergoes rigorous cleaning and surface treatment, resulting in a smooth, rounded particle morphology without sharp edges, effectively reducing the risk of "hard scratches." Furthermore, its low metal ion leaching prevents contamination of the wafer surface and ensures stable device electrical performance. In optical glass polishing, white corundum also achieves high transmittance and low scattering, meeting the requirements of high-end optical systems such as lasers and astronomical telescopes.
5. Wide Compatibility with Various Polishing Carriers and Processes
White corundum micropowder can be flexibly formulated into water-based or oil-based polishing fluids and can be loaded onto polishing cloths, pads, or made into polishing wax, adapting to different equipment and process requirements. White corundum is also popular for its high wear resistance and whiteness in everyday applications such as laminate flooring wear layers, artificial corundum, and sandblasting of porcelain veneers. In the semiconductor and optical fields, its micropowder form pushes performance to the extreme.
In summary, white corundum micropowder, through its high purity, high hardness, precise particle size control, and chemical stability, achieves the perfect balance of "high removal efficiency, low damage, and high cleanliness" in nanoscale ultra-precision polishing. It is not only an upgraded form of traditional abrasives but also a key foundational material supporting the advancement of higher precision in modern microelectronics, optoelectronics, and precision manufacturing, continuously enabling every breakthrough at the forefront of science and technology.
