etch

https://doi.org/10.1351/goldbook.09488
Treatment to remove substrate to a requisite depth from those areas of a surface no longer protected following the exposure and development of an overlaid resist.
Source:
PAC, 2020, 92, 1861. 'Terminology of polymers in advanced lithography (IUPAC Recommendations 2020)' on page 1874 (https://doi.org/10.1515/pac-2018-1215)