Effect of Organic Acids in Copper Chemical Mechanical Planarization Slurry on Slurry Stability and Particle Contamination on Copper Surfaces

Eom, Dae-Hong; Park, Jin-Goo; Lee, Eung-Sug

doi:10.1143/jjap.41.1305

Cited by 14 publications

(8 citation statements)

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“…Contrarily, the transmittance of the CL reached a plateau of 40% within 40 min, and even decreased to 31.5% after saturated with Zn(II). The presence of citric acid was reported to result in a stable suspension of alumina particles in the slurry [18]. The higher percentage of clay minerals and natural organics in CL could lead to a lower sedimentation rate.…”

Section: Sedimentary Rate Of the Sorbentmentioning

confidence: 99%

Adsorption behavior of Zn(II) on calcinated Chinese loess

Tang

Chen

2009

Journal of Hazardous Materials

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Section: Sedimentary Rate Of the Sorbentmentioning

confidence: 99%

Adsorption behavior of Zn(II) on calcinated Chinese loess

Tang

Chen

2009

Journal of Hazardous Materials

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“…Organic and inorganic acids are widely used in the formulation of CMP slurries for etching, inhibition, and slurry particle modification purposes. 23,26,27 X-ray fluorescence ͑XRF͒ analysis was performed in a Spectro XLab2000 commercial wavelength-dispersive XRF system equipped with a molybdenum target to monitor W loss in WN X C Y film. X-ray photoelectron spectroscopy ͑XPS͒ was performed to monitor the surface composition of WN X C Y film.…”

Section: Methodsmentioning

confidence: 99%

Corrosion and Inhibition of WN[sub X]C[sub Y] Barrier during Chemical Mechanical Planarization

Ernur

Terzieva

Schuhmacher

et al. 2005

J. Electrochem. Soc.

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We investigated the mechanism of chemical and galvanic corrosion of tungsten nitride carbide ͑WN X C Y ͒ barrier during Cu chemical mechanical planarization ͑CMP͒. Our results demonstrate that chemical corrosion is caused by the oxidation of tungsten ͑W͒ in the WN X C Y film by H 2 O 2 followed by the dissolution of a tungsten oxide complex, which leads to WN X C Y loss. WN X C Y loss is enhanced during CMP due to galvanic corrosion driven by the Cu/WN X C Y couple. A high loss rate occurs due to the strong potential difference between Cu and WN X C Y in H 2 O 2 -containing slurries. A model representing WN X C Y loss in Cu damascene lines during the CMP process is proposed. It supports WN X C Y loss in the top part of the trench sidewall at the interface with Cu. We demonstrate that the use of HNO 3 instead of H 2 O 2 as the oxidizer, in the formulation of the corrosion-inhibiting model slurries reduces chemical and galvanic corrosion of WN X C Y . Addition of monosaccharides or organic acids prevents excessive Cu loss. Wafer-level tests done with in-house corrosion-inhibiting model slurries show promising Cu and WN X C Y compatibility without significant WN X C Y loss.Copper ͑Cu͒ is selected as the interconnect material of choice for the fabrication of ultralarge scale integrated ͑ULSI͒ circuits due to its lower resistivity and improved electromigration resistance as compared to aluminum ͑Al͒. 1 The damascene process is successfully implemented in order to integrate Cu in ULSI. Unlike Al metallization, the damascene process relies on depositing Cu into the patterned dielectric by electrochemical deposition ͑ECD͒. Because Cu readily diffuses into the dielectric, a diffusion barrier is deposited prior to Cu deposition. Chemical mechanical planarization ͑CMP͒ is used to polish excess Cu overburden and barrier metal to provide surface planarity.In the manufacturing of microelectronic devices Cu is susceptible to corrosion in particular by reacting in oxidizing environments. Corrosion of Cu interconnects during integrated circuit ͑IC͒ manufacturing occurs mostly during the CMP process where Cu is in contact with the CMP slurry. Chemical, photo-, narrow-trench, and galvanic corrosion are reported to be the possible mechanisms. 2-4 Galvanic corrosion occurs when two dissimilar metals are in electrical and in ionic contact. Thus, during the CMP process, slurry acts as the electrolyte providing the ionic contact medium for the barrier metal and Cu, which are in electrical contact. Depending on the electrochemical potential difference, it is either Cu or the barrier that acts as the anode and suffers from enhanced material loss as shown schematically in Fig. 1. Galvanic corrosion has been reported 2,5,6 by several groups.Many materials, including Ta, TaN, Ti, TiN, W, and WN X C Y , are being investigated for use as Cu diffusion barriers. 7-16 In the selection of a barrier material the ease of deposition, step coverage, adhesion to Cu, and adhesion to the dielectric must be considered. The demand for effective diffusion b...

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“…A corrosion inhibitor is also added to the slurry to prevent undesired corrosion due to an oxidation reaction. [5][6][7][8][9] Therefore, to realize precise Cu CMP, control of the competing oxidation and passivation reactions is crucial.…”

Section: Introductionmentioning

confidence: 99%

Growth kinetics of Cu surface layers in H₂O₂–BTA aqueous solutions

Kondoh¹,

Toyama²,

Jin³

et al. 2020

Jpn. J. Appl. Phys.

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Slurries for the chemical mechanical polishing of Cu contain both an oxidizer and a corrosion inhibitor, in addition to abrasives. To understand the chemistry of the Cu surface exposed to slurries, Cu surfaces in benzotriazole (BTA)–hydrogen peroxide (H2O2) aqueous solutions were studied using in situ spectroscopic ellipsometry. A microfluidic optical cell was used so that processing solutions could be changed during in situ observations and the initial surface processes could be successfully observed. A thin surface layer was observed to grow on Cu in the solutions. The growth rate of surface layers on Cu was inversely proportional to the thickness of the growing layer, and the growth then stopped in a self-limiting manner. The growth mechanism is discussed in view of Cu out-diffusion.

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Effect of Organic Acids in Copper Chemical Mechanical Planarization Slurry on Slurry Stability and Particle Contamination on Copper Surfaces

Cited by 14 publications

References 0 publications

Adsorption behavior of Zn(II) on calcinated Chinese loess

Adsorption behavior of Zn(II) on calcinated Chinese loess

Corrosion and Inhibition of WN[sub X]C[sub Y] Barrier during Chemical Mechanical Planarization

Growth kinetics of Cu surface layers in H₂O₂–BTA aqueous solutions

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Effect of Organic Acids in Copper Chemical Mechanical Planarization Slurry on Slurry Stability and Particle Contamination on Copper Surfaces

Cited by 14 publications

References 0 publications

Adsorption behavior of Zn(II) on calcinated Chinese loess

Adsorption behavior of Zn(II) on calcinated Chinese loess

Corrosion and Inhibition of WN[sub X]C[sub Y] Barrier during Chemical Mechanical Planarization

Growth kinetics of Cu surface layers in H2O2–BTA aqueous solutions

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Growth kinetics of Cu surface layers in H₂O₂–BTA aqueous solutions