Unetched

Unetched is an adjective describing a material surface or region that has not undergone an etching process. Etching refers to the deliberate removal of material by chemical or mechanical means to reveal underlying microstructure, composition, or patterns. An unetched surface therefore preserves the original microstructure and surface morphology prior to any etching step.

In metallography and materials science, etching exposes grain boundaries and phases; an unetched specimen will not show these features and may be used for bulk property testing or to preserve corrosion resistance. Some analyses, however, require etching to reveal microstructure, while others rely on the unetched state to study properties without altered contrast.

In microfabrication, unetched regions are areas not exposed to etchants during pattern transfer; they remain pristine or serve as masks for subsequent deposition. The distinction between etched and unetched regions is central to defining features and controlling device performance, as unetched areas can influence electrical properties, adhesion, and surface chemistry.

Preparation and reporting: when presenting results, it is important to indicate whether a sample is unetched, because etching can alter apparent grain size, roughness, or defect visibility. Unetched specimens serve as baseline states for comparison with etched counterparts, and their interpretation depends on the intended analysis.