Interaction Forces Between a Glass Surface and Ceria-Modified PMMA-Based Abrasives for CMP Measured by Colloidal Probe AFM

Armini, Silvia; Burtovyy, Ruslan; Moinpour, Mansour; Luzinov, Igor; Messemaeker, Joke De; Whelan, Caroline M.; Maex, Karen

doi:10.1149/1.2834456

Cited by 11 publications

(16 citation statements)

References 27 publications

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“…The interaction force and composite particle morphology were also described in other works [53,54]. Based on the average pull-off force vs. pH plot, qualitative agreement between the measured adhesion forces and the material removal rate was reached [53]. Furthermore, the depth of the scratch increased with increasing abrasive size of fumed silica abrasive.…”

Section: High Particle Concentration and Agglomerated Particlessupporting

confidence: 52%

“…Also, the larger size of colloidal silica shows a higher number of defects level than the smaller size of colloidal silica. The interaction force and composite particle morphology were also described in other works [53,54]. Based on the average pull-off force vs. pH plot, qualitative agreement between the measured adhesion forces and the material removal rate was reached [53].…”

Section: High Particle Concentration and Agglomerated Particlesmentioning

confidence: 61%

“…On the other hand, novel polymer-core silica-shell composites were proposed by Armini et al [52,53]. Polymethyl methacrylate (PMMA)-based terpolymer particles (diameter 350 nm) were coated with colloidal silica particles.…”

Section: High Particle Concentration and Agglomerated Particlesmentioning

confidence: 99%

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Scratch formation and its mechanism in chemical mechanical planarization (CMP)

2013

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Chemical mechanical planarization (CMP) has become one of the most critical processes in semiconductor device fabrication to achieve global planarization. To achieve an efficient global planarization for device node dimensions of less than 32 nm, a comprehensive understanding of the physical, chemical, and tribo-mechanical/chemical action at the interface between the pad and wafer in the presence of a slurry medium is essential. During the CMP process, some issues such as film delamination, scratching, dishing, erosion, and corrosion can generate defects which can adversely affect the yield and reliability. In this article, an overview of material removal mechanism of CMP process, investigation of the scratch formation behavior based on polishing process conditions and consumables, scratch formation mechanism and the scratch inspection tools were extensively reviewed. The advantages of adopting the filtration unit and the jet spraying of water to reduce the scratch formation have been reviewed. The current research trends in the scratch formation, based on modeling perspective were also discussed.

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Section: High Particle Concentration and Agglomerated Particlessupporting

confidence: 52%

Section: High Particle Concentration and Agglomerated Particlesmentioning

confidence: 61%

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Scratch formation and its mechanism in chemical mechanical planarization (CMP)

2013

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“…Volkov et al 20 modified this method to measure the adhesion force of silica and ceria particles of irregular shape with silica surfaces and correlated it with the polishing rates obtained using slurries containing those abrasives. Similar to Armini et al, 18 they used large silica spheres to mimic a flat silica film surface, but embedded the nanoparticles in a thick layer of epoxy on a wafer surface. They claimed that the silica and ceria nanoparticles, which are only partially embedded in the epoxy, form a sufficiently flat surface.…”

Section: -11mentioning

confidence: 99%

AFM-Based Study of the Interaction Forces between Ceria, Silicon Dioxide and Polyurethane Pad during Non-Prestonian Polishing of Silicon Dioxide Films

Korkmaz

Vahdat

Trotsenko

et al. 2015

ECS J. Solid State Sci. Technol.

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A colloidal AFM-based method was used to understand the role of diallyldimethyl ammonium chloride (DADMAC) molecules in non-Prestonian silicon dioxide removal obtained using ceria-based slurries. A series of force-distance measurements between silicon dioxide films, polyurethane IC1000 polishing pad and ceria abrasives in liquid media with and without DADMAC molecules were made. It was shown that at 15 mM concentration, DADMAC molecules yield non-Prestonian behavior by interfering between ceria particles and the oxide film. The effects of the DADMAC additive on the removal rates of the oxide films and their corresponding coefficients of friction (COFs) values were also investigated. Finally, the correlation between AFM force measurements, removal rates and COF values measured during polishing are discussed. Interestingly, below a threshold COF value of ∼0.23 to 0.24, corresponding to a threshold down pressure of ∼2psi for both 15 mM and 25 mM DADMAC concentration, no oxide film removal was observed. Chemical Mechanical Planarization (CMP) is a critical step during the fabrication of ultra large scale integrated circuits (ULSICs) in the semiconductor industry. Since the feature dimensions of current ICs are continually scaling down (latest technology node of 14 nm was recently announced by Intel corp.), the demands on surface planarity of various films have become more stringent. An improved understanding of polishing mechanisms can help to achieve the desired polishing requirements. These requirements include minimizing defects such as surface roughness, micro-scratches, etc. 1,2One of the main applications of CMP in the front-end-of-the-line is shallow trench isolation (STI) fabrication. The STI 3 structure isolates two adjacent semiconductor device components (transistors, diodes, etc.) preventing electrical current leakage between them. Application of CMP for fabricating these STI structures has been widely studied. However, precise end-point detection during the fabrication of these structures remains a challenge. As a result, due to the non-uniform polishing of the oxide film across the wafer, 4 over-polishing time is almost always required to remove any residual oxide from the nitride areas. This can result in considerable dishing in the oxide-filled trenches in the STI structure. Dishing takes place if the oxide material inside the trenches is polished, especially at the low pressures created by contact with the polishing pad. One efficient method that can minimize dishing is to use a non-Prestonian polishing slurry [5][6][7] which causes negligible removal below a threshold applied downward pressure. Recently, it was shown that a ceria-based slurry containing 15 mM diallyldimethyl ammonium chloride (DADMAC) as an additive resulted in non-Prestonian oxide removal 7 with negligible removal below ∼2 psi applied pressure. Based on the measurements of the adsorption strength of DADMAC molecules on ceria and silica surfaces, using various techniques including thermo-gravimetric analysis (TGA) and UV-visible sp...

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“…4,5 However, we experimentally confirmed the fact that silica and ceria particles can create severe microscratches that negatively affect its effective application to shallow trench isolation CMP. 1 In this paper, we report on potentially attractive mixed abrasive slurry ͑MAS͒ systems that can minimize many of these shortcomings. In addition, these experiments shed some light on the importance of the bond between the polymer core and the inorganic particles in the shell and on the differences between the colloidal silicaand ceria-based MAS systems.…”

mentioning

confidence: 99%

Mixed Organic/Inorganic Abrasive Particles during Oxide CMP

Armini

Whelan

Moinpour

et al. 2008

Electrochem. Solid-State Lett.

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Chemical mechanical planarization ͑CMP͒ of silicon dioxide films was performed using mixed abrasive slurries ͑MASs͒ achieved by mixing in situ polymer and inorganic particles. The results were discussed in terms of material removal rate ͑MRR͒ and defectivity. We compared 30 nm sílica colloids and 14 nm primary size ceria particles. Our experiments shed some light on the importance of the bond between polymer core and inorganic particles in the shell and on the differences between silica-based and ceria-based MASs. Although for the silica-based MAS the MRR passes through a maximum ͑17 nm/min for 2:3 ratio polymer: silica͒, for the ceria-based MAS it increases with the ceria solid content. The polymer:silica ratios used in the experiments spanned in the range from 1:15 to 10:1.Composite structures comprising polymer particles coated by a layer of inorganic particles allow combining several advantageous properties in the same structure. The polymer core shows mechanical properties that are highly tunable by variation of its synthesis parameters, 1 while the major advantage of the silica/ceria coating is that it can be easily modified, in terms of its surface chemistry and morphology. In particular, this kind of composite particle is aimed at improving the chemical mechanical planarization ͑CMP͒ process of easily damaged materials due to the springlike effect coming from the elastic properties of the core. 2 In our previous work, 3 we already presented different polymer core/inorganic shell composite abrasives for CMP applications. In particular, in one type of composite ͑composite B͒, the shell was achieved by maximizing the electrostatic attraction between the silica particles and the terpolymer core. The preparation of composite abrasive B, even if simple, adds an extra synthesis step. The pH during the synthesis must be carefully controlled in order to avoid a decrease in particle stability.Furthermore, in the attempt to optimize the silicon oxide CMP process, it should be considered that both silica-and ceria-based abrasives are very useful. In particular, the ceria-based abrasives present undoubted advantages, such as enhanced chemical affinity toward the silica, which translates into high material removal rate ͑MRR͒, and possible combination with surfactants to increase the silica vs nitride selectivity. 4,5 However, we experimentally confirmed the fact that silica and ceria particles can create severe microscratches that negatively affect its effective application to shallow trench isolation CMP. 1 In this paper, we report on potentially attractive mixed abrasive slurry ͑MAS͒ systems that can minimize many of these shortcomings. In addition, these experiments shed some light on the importance of the bond between the polymer core and the inorganic particles in the shell and on the differences between the colloidal silicaand ceria-based MAS systems. Other ceria-/silica-based MAS systems can be found in the literature. 6,7 ExperimentalThe ceria particles for the CMP experiments were provided by Umicore and have ...

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Interaction Forces Between a Glass Surface and Ceria-Modified PMMA-Based Abrasives for CMP Measured by Colloidal Probe AFM

Cited by 11 publications

References 27 publications

Scratch formation and its mechanism in chemical mechanical planarization (CMP)

Scratch formation and its mechanism in chemical mechanical planarization (CMP)

AFM-Based Study of the Interaction Forces between Ceria, Silicon Dioxide and Polyurethane Pad during Non-Prestonian Polishing of Silicon Dioxide Films

Mixed Organic/Inorganic Abrasive Particles during Oxide CMP

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