Direct electroless plating of Cu on barrier metals

Shingubara, Shoso; Wang, Z.; Ida, Tadao; Sakaue, Hiroyuki; Takahagi, I.

doi:10.1109/iitc.2002.1014925

Cited by 9 publications

(10 citation statements)

References 3 publications

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“…There have been efforts to achieve good adhesion of copper film on various diffusion barriers using electroless plating ͑ELP͒ method by modulating the reduction-oxidation ͑redox͒ potential. 7,8 Although good adhesion of copper on TaN, TiN, and WN was reported, the complexity of the ELP process as compared to the ECD method limits its application to mass production in semiconductor industries. 9 Additionally, it takes relatively long to achieve the aimed thickness of copper films due to the low deposition rate of the ELP process.…”

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confidence: 99%

Effect of Chemical Composition on Adhesion of Directly Electrodeposited Copper Film on TiN

Kim

Duquette

2006

J. Electrochem. Soc.

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Copper citrate ͑Cu-Cit͒ baths are effective mediums for seedless electrochemical deposition ͑ECD͒ of copper with strong adhesion property on TiN. The chemical equilibrium diagrams of chemical fraction vs pH were used to explain the cause of good adhesion of copper deposits on TiN. The kind and the amount of Cu-Cit complexes in a bath were determined according to pH and the concentration ratio of copper and citrate, ͓Cu 2+ ͔/͓Cit −3 ͔. It was found that CuCit − among various Cu-Cit complexes participated in adherent copper reduction on TiN. When more Cu 2 ͑Cit͒OH than CuCit − was contained in a bath, the reduction of CuCit − was hindered and the adhesion property of copper on TiN became degraded. Resultant ECD copper films on TiN, which were deposited in baths of ͓Cu 2+ ͔/͓Cit 3− ͔ = 1 in the existence of CuCit − passed the ASTM D 3359 adhesion test showing strong adhesion.

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confidence: 99%

Effect of Chemical Composition on Adhesion of Directly Electrodeposited Copper Film on TiN

Kim

Duquette

2006

J. Electrochem. Soc.

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“…1 Copper electroless plating and chemical vapor deposition ͑CVD͒ are promising processes for the formation of seed layers for subsequent electroplating. [2][3][4][5][6] Copper electroless plating, which does not require a sputtered Cu seed layer, is an efficient means of filling high-aspect-ratio holes and has become increasingly important in the industry. [3][4][5] Gandikota et al and Andryuschenko and Reid reported that high-aspect via holes were filled completely by electroplating on a Cu seed layer prepared by physical vapor deposition ͑PVD͒ followed by repair by electroless copper plating.…”

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confidence: 99%

Characterization of Electroless-Plated Cu Film over Pd Catalytic Layer Formed by an Ionized Cluster Beam

Wang

Shingubara

Sakaue

et al. 2005

J. Electrochem. Soc.

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A continuous electroless-plated Cu film only 10 nm thick was successfully deposited on a TaN barrier over a 1-nm-thick Pd catalytic layer formed by ionized cluster beam deposition. Secondary ion mass spectrometry ͑SIMS͒ analyses for the electrolessplated Cu films on the 20-nm and 1-nm ionized cluster beam ͑ICB͒-Pd layers showed that the Pd metal had diffused into the Cu and caused a high electrical resistivity of Cu interconnect. The electrical resistivity of Cu interconnects formed by electroless plating on an ICB-deposited Pd catalyst layer decreased with decreasing thickness of the ICB-Pd layer. At an ICB-Pd layer thickness of 1-nm, the electrical resistivity of the overlying Cu interconnect was 2.11 ⍀ cm. Moreover, the deposited film has adhesion strength as high as that of sputtered Cu on TaN, even for the case of the 1-nm-thick Pd catalyst layer. A uniform and continuous 10-nm-thick Cu seed layer was formed by electroless plating over a 1-nm-thick Pd layer, and subsequent Cu electroplating filled all high-aspect-ratio via holes without the appearance of voids.Current damascene copper interconnections are fabricated by electroplating on a sputtered Cu seed layer. However, as the dimensions of interconnections continue to shrink, it is becoming increasingly difficult to form a continuous sputtered Cu film on the sidewalls of fine via holes due to the typically poor step coverage of sputtering processes, resulting in the formation of voids during electroplating. 1 Copper electroless plating and chemical vapor deposition ͑CVD͒ are promising processes for the formation of seed layers for subsequent electroplating. 2-6 Copper electroless plating, which does not require a sputtered Cu seed layer, is an efficient means of filling high-aspect-ratio holes and has become increasingly important in the industry. 3-5 Gandikota et al. and Andryuschenko and Reid reported that high-aspect via holes were filled completely by electroplating on a Cu seed layer prepared by physical vapor deposition ͑PVD͒ followed by repair by electroless copper plating. 7,8 However, the processes proved to be too complicated for practical manufacturing.The authors have investigated the formation of a Pd catalysis layer by ionized cluster beam ͑ICB͒ deposition, which provides highly directional deposition suitable for high-aspect-ratio holes. 9 Using this process, a continuous copper layer could be formed even on high-aspect-ratio holes and trenches by electroless copper plating. Furthermore, the adhesion between the electroless-plated Cu film and the TaN barrier layer was sufficient to endure chemical mechanical polishing ͑CMP͒ at an ICB-Pd layer thickness of 20 nm. 10,11 However, the electrical resistivity of the Cu damascene interconnection was rather high ͑3.5-3.9 ⍀ cm͒, thought to be due to diffusion of Pd into the overlying Cu. In this study, the effect of the thickness of the ICB-Pd layer on the properties of the overlying electroless-deposited Cu film is investigated. ExperimentalICB-Pd films with thickness of 1-20 nm were deposited on t...

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“…The chemical tin plating on copper substrate is a replacement reaction process, in which the tin ions in the solution are deposited on the copper substrate, and the copper atoms in the bulk are dissolved into the solution (Figure 2(g)) [37][38][39]. The concentrations of tin and copper ions in plating solution are 3.46 g L −1 and 1.53 g L −1 after tin plating (Figure S19) (the concentration of tin ion is 5.26 g L −1 in the original tin plating solution), which indicates that tin ions in solution are partially reduced to tin metal layer on the copper substrate.…”

Section: Fabrication and Characterization Of F-cu And F-sn@cumentioning

confidence: 99%

Designing Zinc Deposition Substrate with Fully Preferred Orientation to Elude the Interfacial Inhomogeneous Dendrite Growth

et al. 2022

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The development of zinc-ion batteries with high energy density remains a great challenge due to the uncontrollable dendrite growth on their zinc metal anodes. Film anodes plated on the substrate have attracted increasing attention to alleviate these dendrite issues. Herein, we first point out that both the random crystal orientation and the low metal affinity of the substrate are important factors of zinc dendrite formation. Accordingly, the (1 0 1) fully preferred tin interface layer with high zinc affinity was fabricated by chemical tin plating on (1 0 0) oriented copper. This tin decorated copper substrate can realize high reversible zinc plating/stripping behavior, and full cell using this zinc plated substrate can be operated for more than 1000 cycles with high capacity retention (85.3%) and low electrochemical impedance. The proposed strategy can be also applied to lithium metal batteries, which demonstrates that the substrate orientation regulation and metal affinity design are the promising approaches to achieve dendrite-free metal anode and overcome the challenges of highly reactive metal anodes.

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Direct electroless plating of Cu on barrier metals

Cited by 9 publications

References 3 publications

Effect of Chemical Composition on Adhesion of Directly Electrodeposited Copper Film on TiN

Effect of Chemical Composition on Adhesion of Directly Electrodeposited Copper Film on TiN

Characterization of Electroless-Plated Cu Film over Pd Catalytic Layer Formed by an Ionized Cluster Beam

Designing Zinc Deposition Substrate with Fully Preferred Orientation to Elude the Interfacial Inhomogeneous Dendrite Growth

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