BEOL Solvent Clean Process Study Using Fluoride Containing and Hydroxylamine Based Stripper

Abstract

Solvent clean is a critical process for BEOL post Etch/Asher residue removal technology in AlCu device. Well-controlled metal galvanic corrosion, smooth metal sidewall, metal corrosion prevention before dielectric deposition and free polymer residue remaining are basic requirements of solvent clean process. In this paper, solvent clean process was studied in detail using one fluoride containing stripper and a typical hydroxylamine (HDA) based stripper by the pattern wafers of 0.15um and 0.18um node technology. Those key parameters, including residue removal performance, pattern profile, defectivity, resistivity and reliability, were evaluated. The data showed process optimization was necessary to achieve comparable performance from the stripper's intrinsic property points of view.