Naphtha-Free, Organic, Acid-Based Stripper for Polyisoprene-Based Photoresists and Benzocyclobutene Polymer Removal

Hydrophobic polymers, such as polyisoprene-based photoresists, and benzocyclobutene polymer, are typically stripped or reworked using acidic, hydrocarbon-based formulations. These legacy products are associated with a strong, unpleasant smell and pose health and environmental concerns due to the petroleum solvent, residual naphthalene, and regular presence of polyhydroxyphenol as inhibitors. This study aims to present an alternative stripping solution, offering many technical benefits, including high removal efficiency, enhanced loading capacity, while being compatible with most materials. Derived from plant metabolites, it provides additional improvements, for the workplace safety, the rinsing process and the odor, characterized by a more comforting plant fragrance. The development of this new stripper is presented stepwise, detailing the selection process of the new compounds and the influence of their chemical structures on key performance criteria such as stripping efficiency and metal compatibility. Finally, the characteristics of this innovative stripper are benchmarked against an industry-standard product, with comparative analysis based on morphological observations and metal compatibility data.