Projects per year
Adhesion of silica abrasive nanoparticles to a poly(vinyl alcohol) (PVA) brush surface in post-CMP (chemical-mechanical planarization) cleaning leads to serious problems in yield enhancement of semiconductor fabrication. However, the nanoscale adhesion mechanism and its correlation with process conditions have hardly been understood. In this study, we investigated the influence of ammonia in the cleaning solution on silica nanoparticle adhesion to a PVA surface. By atomic force microscopy (AFM), we directly measured adhesion forces between a nanoscale silica probe and a PVA brush surface in various solutions and found that ammonia has a significant inhibitory effect against silica nanoparticle adhesion to a PVA surface. Importantly, we found that this effect cannot be explained by the electrostatic interactions alone but also involves steric repulsion between silica and hydrated PVA. We also performed molecular-scale three-dimensional scanning force microscopy (3D-SFM) imaging and contact angle measurements and found that ammonia promotes hydration and swelling of PVA. Furthermore, we performed molecular dynamics simulations and found that ammonia promotes dynamic rearrangements of hydrogen-bonding networks (HBNs) at a PVA-water interface, giving extra flexibility to the PVA chains. Such flexibility promotes local swelling of PVA and inhibits silica nanoparticle adhesion to a PVA surface. This provides important guidelines for optimizing nanoscale structures and interactions of brush surfaces and abrasive nanoparticles in post-CMP cleaning.
|Number of pages||13|
|Journal||ACS Applied Nano Materials|
|Early online date||16 Dec 2020|
|Publication status||Published - 22 Jan 2021|
|MoE publication type||A1 Journal article-refereed|
- ammonia water
- poly(vinyl alcohol)
- post-CMP cleaning
- silica nanoparticles
- three-dimensional atomic force microscopy
FingerprintDive into the research topics of 'Inhibition of Silica Nanoparticle Adhesion to Poly(vinyl alcohol) Surfaces by Ammonia-Mediated Hydration: Implications for Effective Post-Chemical-Mechanical Planarization Cleaning'. Together they form a unique fingerprint.
- 1 Finished
Molecular resolution at solid-liquid interfaces
Foster, A., Morais Jaques, Y., Silveira Júnior, O., Ranawat, Y. & Kurki, L.
01/09/2018 → 31/08/2022
Project: Academy of Finland: Other research funding