Developing an Efficient Forward Design Method for Co Post-CMP Cleaning Formulations Based on Nanoparticle Removal Mechanisms

Cobalt (Co) with its low resistivity, superior adhesion property, and void-free seamless fill ability pledges to transform the landscape of integrated circuits in many areas, especially in interconnects and logic contacts. The cleaning of Co surfaces after chemical mechanical polishing (CMP) is the indispensable step since a significant number of defects that include SiO 2 nanoparticles, organic residues, and severe corrosion could occur. The present work proposes an efficient forward design method for Co post-CMP cleaning formulations based on nanoparticle removal mechanisms. Each essential component including the pH regulator, complexing agent, corrosion inhibitor, and surfactant was determined in sequence according to every performance point and mechanism analysis, simultaneously oriented by particle removal efficiencies. Furthermore, the nanoparticle removal mechanisms were elucidated via Derjaguin–Landau–Verwey–Overbeek theory calculations, adsorption isotherm analysis, adhesion force tests, surface energy investigation, zeta potential measurements, and other characterizations.