Process and equipment for recovering developer from photoresist development waste and reusing it

Abstract

A tetraalkylammonium hydroxide (TAAH) solution recovered from a development waste through separation therefrom of impurities such as photoresist is mixed with a surface-active substance to have the surface tension thereof adjusted to a desired one, and then reused as a rejuvenated developer. Thus, the surface-active effect (wetting properties) of the rejuvenated developer recovered from the development waste is properly adjusted and controlled, whereby fine photoresist patterns can be stably and effectively developed. Usable surface-active substances include surfactants, and dissolved photoresist contained in the development waste or a photoresist-containing solution such as a photoresist-containing treated solution derived therefrom. Examples of the method of mixing the recovered TAAH-containing solution with the photoresist-containing solution to prepare the rejuvenated developer include a method wherein the TAAH concentration thereof is adjusted either after or while mixing the two solutions, and a method wherein the TAAH concentrations of the two solutions are respectively adjusted, followed by mixing the two solutions at a proper proportion.

Dependencies are inferred from the claim text.