Utilizing an α,β-Unsaturated Dicarboxylic Acid for a Defect Initiated Residue Removal During Cu post-Chemical Mechanical Planarization Cleaning

Abstract

The development of post-chemical mechanical planarization (p-CMP) cleaning processes is critical for the continued miniaturization of integrated circuit and logic device architecture. In order for further extension of Moore’s Law, the minimization of critical defects is essential. This work focuses on the development of surface-active cleaning chemistries via the implementation of an α,β-unsaturated carboxylic acid additive to create synergy at the liquid-brush-wafer interface. More specifically, the implementation of itaconic acid (ItA) will chemically activate an organic residue (i.e., Cu(I)-BTA film) resulting in effective removal at significantly reduced CoF. This work demonstrates that the conjugated structure present in ItA significantly enhances the removal of organic residues at the surface of a Cu substrate without the expense of effective SiO2 removal resulting in little to no p-CMP cleaning induced defectivity.

Design of “Soft” Cleaning Processes for Emerging Substrates via Stimuli Responsive Chemistry

“…It has recently been reported by Dudek et al that additives such as α,β-unsaturated carboxylic acids can be used to exploit an "overcutting" or defect-activated mode of BTA residue removal from copper substrates. [23] By implementing additional modes of interaction (i.e., π-stacking, H-bonding, conformational relationships, etc. ), the BTA removal can be finely tuned via an "aza-Michael-like" reaction that will result in the formation of a BTA-α, β-unsaturated dicarboxylic acid complex.…”