Study of the cross contamination effect on post CMP in situ cleaning process

Kim, Hee Jin; Bohra, Girish; Yang, Hyucksoo; Ahn, Si-Gyung; Qin, Lu; Koli, Dinesh

doi:10.1016/j.mee.2015.03.033

Cited by 46 publications

(32 citation statements)

References 9 publications

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“…Among various methods used for a post-CMP cleaning, the brush scrubbing method has been accepted as the most efficient way to remove contaminants. 2,3 In this method, a rotating poly(vinyl alcohol) (PVA) brush (Figure 1a) is pressed onto a laterally rotating wafer in an aqueous environment. To improve the efficiency of scrubbing, various process conditions and methods have been explored.…”

Section: Introductionmentioning

confidence: 99%

Inhibition of Silica Nanoparticle Adhesion to Poly(vinyl alcohol) Surfaces by Ammonia-Mediated Hydration: Implications for Effective Post-Chemical–Mechanical Planarization Cleaning

Ikarashi

Yoshino

Nakajima

et al. 2020

ACS Appl. Nano Mater.

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Adhesion of silica abrasive nanoparticles to a poly(vinyl alcohol) (PVA) brush surface in a post-CMP (chemical mechanical planarization) cleaning leads to serious 1 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.

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Section: Introductionmentioning

confidence: 99%

Inhibition of Silica Nanoparticle Adhesion to Poly(vinyl alcohol) Surfaces by Ammonia-Mediated Hydration: Implications for Effective Post-Chemical–Mechanical Planarization Cleaning

Ikarashi

Yoshino

Nakajima

et al. 2020

ACS Appl. Nano Mater.

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“…However, the surface and inside the pore structure of PVA brushes are contaminated with the particles, organic residues, and pad debris (Figure 4a), which can be transported to the next wafers and cause cross-contamination of the wafers during the brush scrubbing [56,58]. More cross-contamination is observed on the wafer surfaces when the contact pressure and contact area between the brush and the wafer increase [59]. Also, the longer brush contact time (lower brush rotation speed) results in more cross-contaminated particles on the wafers.…”

Section: Brush-induced Cross-contamination During Post Cmp Cleaningmentioning

confidence: 99%

Chemical Mechanical Planarization-Related to Contaminants: Their Sources and Characteristics

Seo¹

2021

Emerging Contaminants

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Chemical mechanical planarization (CMP) process has been widely used to planarize a variety of materials including dielectrics, metal, and semiconductors in Si-based semiconductor devices. It is one of the most critical steps to achieve the nanolevel wafer and die scale planarity. However, various contaminants are observed on the wafer surfaces after the CMP process, and they become the most critical yield detractor over many generations of rapidly diminishing feature sizes because they have the most direct impacts on device performance and reliability. This book chapter provides (1) CMP consumables-induced contaminants such as residual particles, surface residues, organic residues, pad debris and metallic impurities, pad contamination, watermark, etc., (2) brush-induced cross-contamination during post CMP cleaning, (3) post-CMP cleaning for removing these contaminants. Fundamental understanding of the formation of various types of CMP contaminants and their characteristics will significantly benefit the development of next-generation CMP slurries and post-CMP cleaning solutions.

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“…Kim et al [17] reported the distribution of residual particles due to cross-contamination on a wafer when the wafer rotation speed and brush gap are changed, that is, the amount of compression of a PVA roller brush. The authors reported the generation of a characteristic recontamination pattern that transfers brush nodule shapes.…”

Section: Relation To Cross-contaminationmentioning

confidence: 99%

“…Brush scrubbing, a type of contact cleaning widely used for post-CMP cleaning, causes crosscontamination [14][15]. Contamination involves transferring the characteristic brush nodule shape patterns on a wafer after cleaning [16][17]. However, the effects of rotating both the brush and wafer have not been clarified.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Nodule Deformation on Cleaning of PVA Roller Brushes and its Relation to Cross-contamination

Hosaka

Miyaki

Mizushima

et al. 2021

J. Photopol. Sci. Technol.

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Study of the cross contamination effect on post CMP in situ cleaning process

Cited by 46 publications

References 9 publications

Inhibition of Silica Nanoparticle Adhesion to Poly(vinyl alcohol) Surfaces by Ammonia-Mediated Hydration: Implications for Effective Post-Chemical–Mechanical Planarization Cleaning

Inhibition of Silica Nanoparticle Adhesion to Poly(vinyl alcohol) Surfaces by Ammonia-Mediated Hydration: Implications for Effective Post-Chemical–Mechanical Planarization Cleaning

Chemical Mechanical Planarization-Related to Contaminants: Their Sources and Characteristics

Nodule Deformation on Cleaning of PVA Roller Brushes and its Relation to Cross-contamination

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