photoresist (rus. фоторезист) — light or X-ray sensitive material on the polymer basis, which is used for film coating application onto a substrate during the lithography by exposing it to light (X-ray) through the projection mask with projected elements of an electronic circuit and further exposure development (etching in the solvent) so as the circuit image is transferred to the substrate.

Description

Depending on the nature of changes in the structure and properties due to irradiation, photoresists are divided into positive and negative. If a film is polymerised and loses solubility due to irradiation, then solvent treatment (development) removes the non-exposed areas only, and on the substrate there is a negative mask. Such photoresists are called negative. If after the exposure the photoresist becomes soluble, then non-exposed areas are removed after the irradiation and development of the mask and as a result there is a positive mask on the substrate. Such photoresists are called positive. Positive photoresists allow for a more accurate reproduction of fine geometric details of the image as compared with the negative one. Positive photoresists are fabricated from phenolic or cresolic formaldehyde resins with o-naphthoquinone diazides, negative photoresists are made of polyvinyl alcohol and chromic acid salts or cyclised rubber doped with additives that cause macromolecule bridging when exposed to radiation.

Author

  • Gusev Alexander I.

Source

  1. Gusev A. I. Nanomaterials, Nanostructures, and Nanotechnologies (in Russian) // Fizmatlit, Moscow (2007) - 416 pp.

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