Postetch

Postetch refers to the suite of processes performed after an etching step in microfabrication. Etching is used to remove selected material to create patterns; postetch processes clean, repair, and stabilize the surface to enable reliable subsequent steps such as deposition, lithography, and packaging.

Common postetch activities include residue removal, surface cleaning, drying, and surface passivation or smoothing. Wet chemical cleans (e.g., solvents, oxidizers) and dry plasma or vapor cleaners are used. Surface passivation may involve oxide regrowth or thin film deposition to protect features and reduce roughness. Metrology checks assess etch depth, sidewall profiles, roughness, and contamination.

Applications encompass semiconductor device fabrication, microelectromechanical systems (MEMS), nanofabrication, and printed electronics. In each case, postetch quality influences device yield, adhesion of subsequent layers, and overall reliability.

Considerations include material compatibility, damage avoidance, and process integration. Postetch steps must minimize stiction, corrosion, or redeposition of etch byproducts, and are often tailored to the material system and equipment.

See also: etching, post-cleaning, surface treatment, plasma cleaning.