mask

synonym: photomask
https://doi.org/10.1351/goldbook.09523
Transparent substrate pre-patterned with the desired image that is inserted into the incident beam in photo- and X-ray lithography.
Notes:
  1. A dark field mask is used with a positive tone photoresist and a bright field mask with a negative tone photoresist.
  2. Masks are typically transparent fused silica blanks with a pattern defined in a chrome film using direct-write lithography.
Source:
PAC, 2020, 92, 1861. 'Terminology of polymers in advanced lithography (IUPAC Recommendations 2020)' on page 1879 (https://doi.org/10.1515/pac-2018-1215)