Atomic layer deposition of dielectric Y<sub>2</sub>O<sub>3</sub> thin films from a homoleptic yttrium formamidinate precursor and water

Boysen, Nils; Zanders, David; Berning, Thomas; Beer, Sebastian; Rogalla, Detlef; Bock, Claudia; Devi, Anjana

doi:10.1039/d0ra09876k

Cited by 17 publications

(22 citation statements)

References 40 publications

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“…The considerably lower onset temperature of evaporation and melting point for [Ir(COD)(DPfAMD)] might be explained by a lower degree of intermolecular van-der-Waals interactions due to the smaller endocyclic (-H) substituent and is moreover in line with our previous studies on yttrium formamidinate complexes. [37,38] The onset temperature of decomposition derived by DSC from our TG measurements is the lowest (176 °C) for [Ir(COD)(DPfAMD)], followed by [Ir(COD)(DPDMG)] (198 °C) and [Ir(COD)(DPAMD)] (211 °C). The differences seen in the decomposition points of the complexes is further supported by the high residual weights seen for all the complexes, while [Ir(COD)(DPfAMD)] features the highest residual weight of 58.0 % after subsequent heating to 550 °C.…”

Section: Thermal Evaluationmentioning

confidence: 92%

High-performance iridium thin films for water splitting by CVD using new Ir(I) precursors

Boysen

Wree

Zanders

et al. 2022

Preprint

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Thin films of iridium can be utilized in a wide range of applications and are particularly interesting for catalytic transformations. For the scalable deposition of functional Ir thin films, metal-organic chemical vapor deposition (MOCVD) is the method of choice, for which organometallic precursors that embody a high volatility and thermal stability need to be specifically tailored. Herein, we report the synthesis, analysis, and evaluation of new volatile Ir(I)-1,5-cyclooctadiene complexes bearing all-nitrogen coordinating guanidinate (DPDMG), amidinate (DPAMD) and formamidinate (DPfAMD) ligands. The amidinate-based Ir complex [Ir(COD)(DPAMD)] together with O2 was implemented in MOCVD experiments resulting in highly crystalline, dense, and conductive Ir films on a variety of substrate materials. The Ir deposits achieved an outstanding electrochemical performance with overpotentials in the range of 50 mV at –10 mA‧cm-2 for catalytic hydrogen evolution reaction (HER) in acidic solution. The ability to deposit Ir layers via MOCVD exhibiting promising functional properties is a significant step towards large scale applications.

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Section: Thermal Evaluationmentioning

confidence: 92%

High-performance iridium thin films for water splitting by CVD using new Ir(I) precursors

Boysen

Wree

Zanders

et al. 2022

Preprint

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“…The recent reports on the closely related metal formamidinates as precursors are also equally promising, as demonstrated in ALD processing of SnS 60 and CaS. 61 Beneficially, the formamidinate ligand features a high compatibility with RE ions, as demonstrated for Y 62,63 and La, 64,65 facilitating the growth of REO thin films via ALD.…”

Section: ■ Introductionmentioning

confidence: 98%

Ferromagnetic Europium Sulfide Thin Films: Influence of Precursors on Magneto-Optical Properties

et al. 2021

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Europium sulfide (EuS) thin films are appealing as ferromagnetic semiconductors and luminescent and optomagnetic materials owing to their unique functional properties. With the emerging field of spintronics and magneto-optical devices, chemical vapor deposition (CVD) offers a versatile platform to tune the material properties and the method to fabricate device structures needed for such applications. Herein, we report the growth of high-quality cubic EuS via a versatile CVD process where the new Eu(III) precursors employed facilitate the formation of the target EuS layers under moderated process conditions. Based on the prior evaluation of the physicochemical properties of these precursors using thermal analysis and density functional theory studies, adequate volatility, thermal stability, and sufficient reactivity toward potential co-reactants, namely, elemental sulfur, could be inferred. Thus, the use of toxic hydrogen sulfide generally needed for sulfide film depositions could be avoided, which is a significant advantage in terms of simplifying the deposition process. The as-deposited thin films were analyzed in terms of the structure, composition, and morphology, revealing highly oriented polycrystalline and stoichiometric EuS films. UV/vis measurements yielded a band gap of around 1.6 eV, and Raman spectroscopy exhibited a coupling between the phonons and electron spin systems of EuS. These findings, together with the soft ferromagnetic character of the films derived from semiconducting quantum interference device measurements, signify the potential of CVD-grown EuS for future technological applications.

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“…[ 18 ] Cubic ZrO 2 is also a high‐κ material, with its κ‐value as high as ≈30. [ 19,20 ] Also, the ALD of Y 2 O 3 is relatively well established, [ 21–23 ] making replacing the Al 2 O 3 IL with the Y 2 O 3 IL or Al‐doping with Y‐doping feasible. According to this idea, this work exploits the adoption of the Y 2 O 3 IL or Y‐doping in ZrO 2 for the next‐generation DRAM capacitor.…”

Section: Introductionmentioning

confidence: 99%

The Contrasting Impacts of the Al₂O₃ and Y₂O₃ Insertion Layers on the Crystallization of ZrO₂ Films for Dynamic Random Access Memory Capacitors

Seo

Yeu

Kwon

et al. 2022

Adv Elect Materials

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Increasing capacitance density could be achieved by mainly two methods: increasing the capacitor node area and adopting higher dielectric constant (κ) material. The former relates mostly to integration issues, such as deep capacitor hole etching with an aspect ratio over 50 and filling the hole with the conformal electrode material. The latter is mainly a material issue, requiring appropriate material selection and an extremely conformal film deposition process. It also must be compatible with the electrode material, which means no adverse interfacial reaction and phase-pure high-κ film growth.Given the industry-compatible and matured electrode fabrication process of TiN grown by the atomic layer deposition (ALD) process, ZrO 2 has been the leading high-κ material in DRAM fabrication. This is because the crystalline structure of the thin-film ZrO 2 transforms from the medium-κ (≈20) monoclinic phase to the high-κ (>≈40) tetragonal phase due to the surface-energy effect. [6,7] Also, the ALD process of ZrO 2 is well matured to secure mass production. However, undoped ZrO 2 has suffered from a high leakage current problem. The problem could be ascribed to the local current flow through the grain boundaries of the polycrystalline ZrO 2 [8] and the n-type nature (the Fermi level is close to the conduction band edge) of the material by the presence of oxygen vacancies. [9,10] This problem has been overcome by adopting a thin Al 2 O 3 insertion layer (IL) for the relatively thicker ZrO 2 or doping the ZrO 2 with Al for thinner films. [8][9][10][11][12] However, such a strategy has sacrificed capacitance density owing to the inclusion of the lowκ amorphous Al 2 O 3 layer (κ ∼ 6-9) or the degraded crystallinity of the Al-doped ZrO 2 . [10,13,14] Therefore, the DRAM industry has spent the enormous effort to optimize the dielectric stack structure, but it has become evident that next-generation dielectric material is necessary for further scaling.Among the diverse candidates with even higher κ-values, SrTiO 3 showed a severe incompatibility with the TiN electrode. [15,16] Hf-doping into the ZrO 2 could be a viable and immediate option, but it involves a risk of loss of discharging density and slow operation speed. This problem is owing to the possible involvement of the (anti-) ferroelectric effect of the Hf-doped This study examines the influences of the Al 2 O 3 and Y 2 O 3 insertion layers (ILs) on the structural and electrical features of ZrO 2 thin films for their application to dynamic random access memory capacitors. The ultra-thin Al 2 O 3 IL (0.1-0.2 nm) dissolves into the ZrO 2 layers, which causes the top and bottom portions of the ZrO 2 film to merge and have smaller lattice parameters. However, the thicker Al 2 O 3 IL (>≈0.4 nm) forms a continuous layer and separates the top and bottom portions of the ZrO 2 film. Interestingly, the diffusion of Al does not occur in this case. Overall, the dielectric constant (κ) of the ZrO 2 /Al 2 O 3 /ZrO 2 film is lower than that of the undoped ZrO 2 film due to the involveme...

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Atomic layer deposition of dielectric Y₂O₃ thin films from a homoleptic yttrium formamidinate precursor and water

Abstract: In this work, the application of tris(N,N′-diisopropyl-formamidinato)yttrium(iii) [Y(DPfAMD)3] as a precursor in a water-assisted thermal atomic layer deposition (ALD) process for the fabrication of device quality Y2O3 thin films is demonstrated.

Cited by 17 publications

References 40 publications

High-performance iridium thin films for water splitting by CVD using new Ir(I) precursors

High-performance iridium thin films for water splitting by CVD using new Ir(I) precursors

Ferromagnetic Europium Sulfide Thin Films: Influence of Precursors on Magneto-Optical Properties

The Contrasting Impacts of the Al₂O₃ and Y₂O₃ Insertion Layers on the Crystallization of ZrO₂ Films for Dynamic Random Access Memory Capacitors

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Atomic layer deposition of dielectric Y2O3 thin films from a homoleptic yttrium formamidinate precursor and water

Abstract: In this work, the application of tris(N,N′-diisopropyl-formamidinato)yttrium(iii) [Y(DPfAMD)3] as a precursor in a water-assisted thermal atomic layer deposition (ALD) process for the fabrication of device quality Y2O3 thin films is demonstrated.

Cited by 17 publications

References 40 publications

High-performance iridium thin films for water splitting by CVD using new Ir(I) precursors

High-performance iridium thin films for water splitting by CVD using new Ir(I) precursors

Ferromagnetic Europium Sulfide Thin Films: Influence of Precursors on Magneto-Optical Properties

The Contrasting Impacts of the Al2O3 and Y2O3 Insertion Layers on the Crystallization of ZrO2 Films for Dynamic Random Access Memory Capacitors

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Atomic layer deposition of dielectric Y₂O₃ thin films from a homoleptic yttrium formamidinate precursor and water

The Contrasting Impacts of the Al₂O₃ and Y₂O₃ Insertion Layers on the Crystallization of ZrO₂ Films for Dynamic Random Access Memory Capacitors