Planarisering

Planarisering is a term used in materials science and manufacturing to describe methods that achieve a flat, uniform surface by reducing topography variations across a substrate. The goal is to produce a near-ideal planar surface to enable reliable subsequent processing, such as lithography, deposition, bonding, or coating.

Common methods include chemical mechanical polishing (CMP), which uses a slurry with abrasive particles and a polishing pad to remove material at higher regions more quickly than lower regions. Other techniques include etch-back or chemical polishing, deposition of planarizing layers followed by selective removal, and mechanical polishing. In semiconductor fabrication, CMP is the dominant planarisering step after deposition of dielectric or metal layers to produce a smooth, flat surface for the next lithography layer.

Planarisering is critical in various industries. In microelectronics, it enables uniform layer thickness, reduces step height variations, and improves device yield. In photovoltaic manufacturing, planarization improves the uniformity of subsequent thin-film deposition. In display production, it helps ensure uniform color and brightness across panels. In optics and coatings, planarization reduces scattering and improves coating adhesion.

Challenges include controlling surface planarity to within tight tolerances, preventing defects such as scratches or dishing and erosion, and managing process-induced stress. Selection of materials, slurry chemistry, pad materials, and process parameters are important to achieve desired planarity without damaging underlying structures.