Certain ortho-quinone diazides such as 2-diazo-1-naphthol-5-sulfonic acid and the -4-sulfonic acid, having the formulas ##STR2## respectively, are useful commercially as precursors for their corresponding sulfonamides and esters which are used as sensitizers for photoresists and electron beam resists; see for example U.S. Pat. Nos. 3,046,118 and 3,852,771. Each class of photoresists has an absorption maximum at a certain wavelength region. The above light sensitive compounds absorb in the near ultraviolet region at about 400 nanometers wavelength or below and have very little absorption beyond about 450 nanometers. It would be desirable to expand the region of absorptivity of photoresists to longer wavelengths, particularly because the common lasers used for high resolution recording and holography are the argon ion laser, which can emit at about 488 nanometers, and the helium-cadmium laser which can emit at 441.6 nanometers.
USPTO Backgrounds
USPTO Backgrounds