An environmentally friendly photoresist and ashing residue remover for Cu/low-k devices

Developed an effective removal solvent for photoresist and its ashing residue for use in copper wire/low-dielectric interlayer devices that significantly lowers the risk of harming the environment. The inhibition of Cu corrosion is very important in these devices, and benzotriazole (BTA, C₆H₅N₃) is usually used as the corrosion inhibitor. However, BTA creates mutagenicity and biodegrades poorly. We investigated several typical heterocyclic nitrogen compounds such as Cu inhibitor to replace BTA and studied their optimum compositions. We found that uric acid (C₅N₄O₃) was the best corrosion inhibitor for Cu. Moreover, this remover which is composed mainly of amino alcohol, uric acid, and H₂O can be applied to low-k films by optimizing its H₂O ratio. It not only effectively removes the ashing residue on Cu/low-k devices, but also effectively reduces the environmental impact because the rinse wastewater containing remover can be completely treated at the fabrication site with ordinary biological processes