Formation of highly reliable Cu/low-k interconnects by using CVD Co barrier in dual damascene structures

Jung, Hye Kyung; Lee, Hyun‐Bae; Tsukasa, Matsuda; Jung, Eun Ji; Yun, Ji-Hoon; Lee, Jong Myeong; Choi, Gil Heyun; Choi, Si‐Young; Chung, Chee Won

doi:10.1109/irps.2011.5784492

Cited by 23 publications

(23 citation statements)

References 10 publications

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“…11,12 Thus, a sidewall material is required in which the adhesion strength is not affected by impurities. [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] The relationship between the adhesion strength and interfacial energy can be expressed by the Young-Dupre equation. The lower interfacial energy between two materials produces high adhesion strength.…”

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confidence: 99%

“…[13][14][15] Due to their lattice constants, Ru (hcp), Os (hcp), and Co (fcc/hcp) have an advantage in their adhesion with Cu. 15 More recent studies have demonstrated an enhanced EM lifetime using either a CVD-Co liner or CVD-Ru liner z E-mail: Hideharu.Shimizu@tn-sanso.co.jp in interconnects, compared with those that use PVD-Ta; [13][14][15][16][17][18][19][20] in these studies, however, PVD-TaN was used as the barrier metal.…”

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confidence: 99%

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Self-Assembled Nano-Stuffing Structure in CVD and ALD Co(W) Films as a Single-Layered Barrier/Liner for Future Cu-Interconnects

Shimizu

Kumamoto

Shima

et al. 2013

ECS J. Solid State Sci. Technol.

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Cobalt film with tungsten [Co(W)] has the potential to be an effective single-layered barrier/liner in interconnects, due to its good adhesion with Cu, low resistivity compared with TaN, and comparable barrier properties to TaN. To reduce the resistivity of Co(W), oxygen-free Co(W) was fabricated from oxygen-free precursors, bis(N-tert-butyl-N′-ethylpropionamidinato) cobalt and bis(tert-butylimino)bis(dimethylamino) tungsten, by chemical vapor deposition (CVD) and atomic layer deposition (ALD). Our results showed that W addition improved the barrier properties of both CVD-Co(W) and ALD-Co(W) against Cu diffusion. The diffusion coefficient of Cu in Co(W) was reduced by W addition. The activation energy of Cu in CVD-Co(W) and ALD-Co(W) was 1.5 eV and 1.7–1.8 eV, respectively; whereas that in CVD-Co was 1.0 eV. Improvement in the barrier properties of Co(W) was attributed to the amorphous-like structure created by W. High-resolution transmission electron microscopy and multivariate spectral analysis of the nanoscale properties of Co(W) revealed that the improvement in the barrier properties was due to the self-assembled segregation of W atoms at the grain boundary. The segregated W atoms in both CVD-Co(W) and ALD-Co(W) films may act as a stuffing material. These results suggest Co(W), especially ALD-Co(W), as a promising material for Cu-interconnects in future ultra-large-scale integrated circuits.

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confidence: 99%

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confidence: 99%

Self-Assembled Nano-Stuffing Structure in CVD and ALD Co(W) Films as a Single-Layered Barrier/Liner for Future Cu-Interconnects

Shimizu

Kumamoto

Shima

et al. 2013

ECS J. Solid State Sci. Technol.

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“…11,12 Therefore, for the sidewall, other materials, in which adhesion strength is not affected by impurities, must be developed. [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] From the viewpoint of surface engineering, Young-Dupre's equation expresses the relationship between adhesion strength and interfacial energy. Lower interfacial energy between two materials produces high adhesion strength.…”

mentioning

confidence: 99%

“…15 Some studies have recently resulted in enhanced EM lifetime using either a CVD-Co liner or CVD-Ru liner in Cu-interconnects z E-mail: Hideharu.Shimizu@tn-sanso.co.jp instead of using PVD-Ta. [13][14][15][16][17][18][19][20] However, in those studies, PVD-TaN was still used as the barrier metal.…”

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confidence: 99%

CVD and ALD Co(W) Films Using Amidinato Precursors as a Single-Layered Barrier/Liner for Next-Generation Cu-Interconnects

Shimizu

Suzuki

Nogami

et al. 2013

ECS J. Solid State Sci. Technol.

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Cobalt film with tungsten addition [Co(W)] has the potential to be an effective single-layered barrier/liner in Cu-interconnects owing to its good adhesion with Cu, a lower resistivity than TaN, and an improved barrier property with respect to cobalt films. Our previous study on chemical-vapor-deposited (CVD) Co(W) using carbonyl precursors clarified, however, that WO3 included in the films increased the resistivity. In this current study, to reduce the resistivity of Co(W), oxygen-free process for Co(W) films were designed using two oxygen-free amidinato precursors, bis(N-tert-butyl-N′-ethylpropionamidinato) cobalt and bis(tert-butylimino)bis(dimethylamino)tungsten, by chemical vapor deposition (CVD) and atomic layer deposition (ALD) at 350–400°C. Deposition process were designed by employing quantum chemical calculation, in which NH3 were chosen as a reducing reagent for the sake of the low activation energy of deposition. NH3 actually acted effective reducing reagent for Co or Co(W) deposition using amidinato precursors in our research. Co(W) films using amidinato precursors and NH3 contained no oxygen and a few amounts of nitrogen. Nitrogen, however, were easily eliminated by annealing at 400°C. Therefore, Co(W) films using amidinato precursors were so high quality to have lower resistivity than Co(W) films using carbonyl precursors or conventional PVD-TaN.

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“…Cobalt is used in a wide variety of technological applications: with a higher sticking coefficient toward copper, cobalt has been used to replace tantalum as a lining material within interconnect trenches in microelectronic devices. , The cobalt layer allows for better copper seed layer coverage thereby reducing copper agglomeration and void formation . Thin films of cobalt, which are ferromagnetic, may be layered with nonmagnetic metals to form devices that take advantage of giant magnetoresistance. , These devices can be used in magnetic data storage media.…”

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confidence: 99%

Cobalt(I) Olefin Complexes: Precursors for Metal–Organic Chemical Vapor Deposition of High Purity Cobalt Metal Thin Films

et al. 2016

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We report the synthesis and characterization of a family of organometallic cobalt(I) metal precursors based around cyclopentadienyl and diene ligands. The molecular structures of the complexes cyclopentadienyl-cobalt(I) diolefin complexes are described, as determined by single-crystal X-ray diffraction analysis. Thermogravimetric analysis and thermal stability studies of the complexes highlighted the isoprene, dimethyl butadiene, and cyclohexadiene derivatives [(C5H5)Co(η(4)-CH2CHC(Me)CH2)] (1), [(C5H5)Co(η(4)-CH2C(Me)C(Me)CH2)] (2), and [(C5H5)Co(η(4)-C6H8)] (4) as possible cobalt metal organic chemical vapor deposition (MOCVD) precursors. Atmospheric pressure MOCVD was employed using precursor 1, to synthesize thin films of metallic cobalt on silicon substrates under an atmosphere (760 torr) of hydrogen (H2). Analysis of the thin films deposited at substrate temperatures of 325, 350, 375, and 400 °C, respectively, by scanning electron microscopy and atomic force microscopy reveal temperature-dependent growth features. Films grown at these temperatures are continuous, pinhole-free, and can be seen to be composed of hexagonal particles clearly visible in the electron micrograph. Powder X-ray diffraction and X-ray photoelectron spectroscopy all show the films to be highly crystalline, high-purity metallic cobalt. Raman spectroscopy was unable to detect the presence of cobalt silicides at the substrate/thin film interface.

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Formation of highly reliable Cu/low-k interconnects by using CVD Co barrier in dual damascene structures

Cited by 23 publications

References 10 publications

Self-Assembled Nano-Stuffing Structure in CVD and ALD Co(W) Films as a Single-Layered Barrier/Liner for Future Cu-Interconnects

Self-Assembled Nano-Stuffing Structure in CVD and ALD Co(W) Films as a Single-Layered Barrier/Liner for Future Cu-Interconnects

CVD and ALD Co(W) Films Using Amidinato Precursors as a Single-Layered Barrier/Liner for Next-Generation Cu-Interconnects

Cobalt(I) Olefin Complexes: Precursors for Metal–Organic Chemical Vapor Deposition of High Purity Cobalt Metal Thin Films

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