Depth of focus

{
  "id": "MLC-T-CHM-013030",
  "term": "Depth of focus",
  "field": "Chemistry",
  "definition": "The distance along the optical axis over which a projected image remains in acceptable focus. In photolithography, this parameter defines the tolerance for variations in the substrate's surface height while still achieving the desired feature resolution. The depth of focus is inversely proportional to the square of the numerical aperture of the projection lens and directly proportional to the wavelength of the light source used.",
  "subject": "Polymer",
  "see_also": [
    "image"
  ],
  "references": [
    "PAC, 2020, 92, 1861. 'Terminology of polymers in advanced lithography (IUPAC Recommendations 2020)' on page 1870 (https://doi.org/10.1515/pac-2018-1215)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/depth-of-focus/"
}