1
|
Yoon H, Lee Y, Lee GY, Seo S, Park BK, Chung TM, Oh IK, Kim H. Role of a cyclopentadienyl ligand in a heteroleptic alkoxide precursor in atomic layer deposition. J Chem Phys 2024; 160:024302. [PMID: 38189606 DOI: 10.1063/5.0182690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 12/12/2023] [Indexed: 01/09/2024] Open
Abstract
Alkoxide precursors have been highlighted for depositing carbon-free films, but their use in Atomic Layer Deposition (ALD) often exhibits a non-saturated growth. This indicates no self-limiting growth due to the chain reaction of hydrolysis or ligand decomposition caused by β-hydride elimination. In the previous study, we demonstrated that self-limiting growth of ALD can be achieved using our newly developed precursor, hafnium cyclopentadienyl tris(N-ethoxy-2,2-dimethyl propanamido) [HfCp(edpa)3]. To elucidate the growth mechanism and the role of cyclopentadienyl (Cp) ligand in a heteroleptic alkoxide precursor, herein, we compare homoleptic and heteroleptic Hf precursors consisting of N-ethoxy-2,2-dimethyl propanamido (edpa) ligands with and without cyclopentadienyl ligand-hafnium tetrakis(N-ethoxy-2,2-dimethyl propanamido) [Hf(edpa)4] and HfCp(edpa)3. We also investigate the role of a Cp ligand in growth characteristics. By substituting an alkoxide ligand with a Cp ligand, we could modify the surface reaction during ALD, preventing undesired reactions. The last remaining edpa after Hf(edpa)4 adsorption can undergo a hydride elimination reaction, resulting in surface O-H generation. In contrast, Cp remains after the HfCp(edpa)3 adsorption. Accordingly, we observe proper ALD growth with self-limiting properties. Thus, a comparative study of different ligands of the precursors can provide critical clues to the design of alkoxide precursors for obtaining typical ALD growth with a saturation behavior.
Collapse
Affiliation(s)
- Hwi Yoon
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-Ro, Seodaemun-Gu, Seoul 03722, South Korea
| | - Yujin Lee
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-Ro, Seodaemun-Gu, Seoul 03722, South Korea
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA
| | - Ga Yeon Lee
- Thin Film Materials Research Center, Korea Research Institute of Chemical Technology, 141 Gajeong-Ro, Yuseong-gu, Daejeon 34114, South Korea
| | - Seunggi Seo
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-Ro, Seodaemun-Gu, Seoul 03722, South Korea
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA
| | - Bo Keun Park
- Thin Film Materials Research Center, Korea Research Institute of Chemical Technology, 141 Gajeong-Ro, Yuseong-gu, Daejeon 34114, South Korea
| | - Taek-Mo Chung
- Thin Film Materials Research Center, Korea Research Institute of Chemical Technology, 141 Gajeong-Ro, Yuseong-gu, Daejeon 34114, South Korea
| | - Il-Kwon Oh
- Department of Electrical and Computer Engineering, Ajou University, 206 Worldcup-Ro, Yeongtong-Gu 16499, Suwon, South Korea
- Department of Intelligence Semiconductor Engineering, Ajou University, 206 Worldcup-Ro, Yeongtong-Gu 16499, Suwon, South Korea
| | - Hyungjun Kim
- School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-Ro, Seodaemun-Gu, Seoul 03722, South Korea
| |
Collapse
|
2
|
Kaur P, Mai L, Muriqi A, Zanders D, Ghiyasi R, Safdar M, Boysen N, Winter M, Nolan M, Karppinen M, Devi A. Rational Development of Guanidinate and Amidinate Based Cerium and Ytterbium Complexes as Atomic Layer Deposition Precursors: Synthesis, Modeling, and Application. Chemistry 2021; 27:4913-4926. [PMID: 33470473 PMCID: PMC7986905 DOI: 10.1002/chem.202003907] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/02/2020] [Indexed: 11/06/2022]
Abstract
Owing to the limited availability of suitable precursors for vapor phase deposition of rare-earth containing thin-film materials, new or improved precursors are sought after. In this study, we explored new precursors for atomic layer deposition (ALD) of cerium (Ce) and ytterbium (Yb) containing thin films. A series of homoleptic tris-guanidinate and tris-amidinate complexes of cerium (Ce) and ytterbium (Yb) were synthesized and thoroughly characterized. The C-substituents on the N-C-N backbone (Me, NMe2 , NEt2 , where Me=methyl, Et=ethyl) and the N-substituents from symmetrical iso-propyl (iPr) to asymmetrical tertiary-butyl (tBu) and Et were systematically varied to study the influence of the substituents on the physicochemical properties of the resulting compounds. Single crystal structures of [Ce(dpdmg)3 ] 1 and [Yb(dpdmg)3 ] 6 (dpdmg=N,N'-diisopropyl-2-dimethylamido-guanidinate) highlight a monomeric nature in the solid-state with a distorted trigonal prismatic geometry. The thermogravimetric analysis shows that the complexes are volatile and emphasize that increasing asymmetry in the complexes lowers their melting points while reducing their thermal stability. Density functional theory (DFT) was used to study the reactivity of amidinates and guanidinates of Ce and Yb complexes towards oxygen (O2 ) and water (H2 O). Signified by the DFT calculations, the guanidinates show an increased reactivity toward water compared to the amidinate complexes. Furthermore, the Ce complexes are more reactive compared to the Yb complexes, indicating even a reactivity towards oxygen potentially exploitable for ALD purposes. As a representative precursor, the highly reactive [Ce(dpdmg)3 ] 1 was used for proof-of-principle ALD depositions of CeO2 thin films using water as co-reactant. The self-limited ALD growth process could be confirmed at 160 °C with polycrystalline cubic CeO2 films formed on Si(100) substrates. This study confirms that moving towards nitrogen-coordinated rare-earth complexes bearing the guanidinate and amidinate ligands can indeed be very appealing in terms of new precursors for ALD of rare earth based materials.
Collapse
Affiliation(s)
- Parmish Kaur
- Inorganic Materials ChemistryRuhr University BochumUniversitätsstraße 15044801BochumGermany
| | - Lukas Mai
- Inorganic Materials ChemistryRuhr University BochumUniversitätsstraße 15044801BochumGermany
| | - Arbresha Muriqi
- Tyndall National InstituteUniversity College CorkLee MaltingsCorkT12 R5CPIreland
| | - David Zanders
- Inorganic Materials ChemistryRuhr University BochumUniversitätsstraße 15044801BochumGermany
| | - Ramin Ghiyasi
- Department of Chemistry and Materials ScienceAalto UniversityKemistintie 100076AaltoEspooFinland
| | - Muhammad Safdar
- Department of Chemistry and Materials ScienceAalto UniversityKemistintie 100076AaltoEspooFinland
| | - Nils Boysen
- Inorganic Materials ChemistryRuhr University BochumUniversitätsstraße 15044801BochumGermany
| | - Manuela Winter
- Inorganic Materials ChemistryRuhr University BochumUniversitätsstraße 15044801BochumGermany
| | - Michael Nolan
- Tyndall National InstituteUniversity College CorkLee MaltingsCorkT12 R5CPIreland
| | - Maarit Karppinen
- Department of Chemistry and Materials ScienceAalto UniversityKemistintie 100076AaltoEspooFinland
| | - Anjana Devi
- Inorganic Materials ChemistryRuhr University BochumUniversitätsstraße 15044801BochumGermany
| |
Collapse
|
3
|
Zanders D, Ciftyurek E, Subaşı E, Huster N, Bock C, Kostka A, Rogalla D, Schierbaum K, Devi A. PEALD of HfO 2 Thin Films: Precursor Tuning and a New Near-Ambient-Pressure XPS Approach to in Situ Examination of Thin-Film Surfaces Exposed to Reactive Gases. ACS APPLIED MATERIALS & INTERFACES 2019; 11:28407-28422. [PMID: 31339290 DOI: 10.1021/acsami.9b07090] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A bottom-up approach starting with the development of new Hf precursors for plasma-enhanced atomic layer deposition (PEALD) processes for HfO2 followed by in situ thin-film surface characterization of HfO2 upon exposure to reactive gases via near-ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS) is reported. The stability of thin films under simulated operational conditions is assessed, and the successful implementation of HfO2 dielectric layers in metal-insulator-semiconductor (MIS) capacitors is demonstrated. Among the series of newly synthesized mono-guanidinato-tris-dialkyl-amido class of Hf precursors, one of them, namely, [Hf{η2-(iPrN)2CNEtMe}(NEtMe)3], was representatively utilized with oxygen plasma, resulting in a highly promising low-temperature PEALD process at 60 °C. The new precursors were synthesized in the multigram scale and thoroughly characterized by thermogravimetric analyses, revealing high and tunable volatility reflected by appreciable vapor pressures and accompanied by thermal stability. Typical ALD growth characteristics in terms of linearity, saturation, and a broad ALD window with constant growth of 1.06 Å cycle-1 in the temperature range of 60-240 °C render this process very promising for fabricating high-purity smooth HfO2 layers. For the first time, NAP-XPS surface studies on selected HfO2 layers are reported upon exposure to reactive H2, O2, and H2O atmospheres at temperatures of up to 500 °C revealing remarkable stability against degradation. This can be attributed to the absence of surface defects and vacancies. On the basis of these promising results, PEALD-grown HfO2 films were used as dielectric layers in the MIS capacitor device fabrication exhibiting leakage current densities less than 10-7 A cm-2 at 2 MV cm-1 and permittivities of up to 13.9 without postannealing.
Collapse
Affiliation(s)
| | - Engin Ciftyurek
- Department of Materials Science, Institute of Experimental Physics and Condensed Matter , Heinrich-Heine-University Düsseldorf , 40225 Düsseldorf , Germany
| | | | | | | | | | | | - Klaus Schierbaum
- Department of Materials Science, Institute of Experimental Physics and Condensed Matter , Heinrich-Heine-University Düsseldorf , 40225 Düsseldorf , Germany
| | | |
Collapse
|
4
|
Devlin-Mullin A, Todd NM, Golrokhi Z, Geng H, Konerding MA, Ternan NG, Hunt JA, Potter RJ, Sutcliffe C, Jones E, Lee PD, Mitchell CA. Atomic Layer Deposition of a Silver Nanolayer on Advanced Titanium Orthopedic Implants Inhibits Bacterial Colonization and Supports Vascularized de Novo Bone Ingrowth. Adv Healthc Mater 2017; 6. [PMID: 28321991 DOI: 10.1002/adhm.201700033] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 02/01/2017] [Indexed: 11/10/2022]
Abstract
Joint replacement surgery is associated with significant morbidity and mortality following infection with either methicillin-resistant Staphylococcus aureus (MRSA) or Staphylococcus epidermidis. These organisms have strong biofilm-forming capability in deep wounds and on prosthetic surfaces, with 103 -104 microbes resulting in clinically significant infections. To inhibit biofilm formation, we developed 3D titanium structures using selective laser melting and then coated them with a silver nanolayer using atomic layer deposition. On bare titanium scaffolds, S. epidermidis growth was slow but on silver-coated implants there were significant further reductions in both bacterial recovery (p < 0.0001) and biofilm formation (p < 0.001). MRSA growth was similarly slow on bare titanium scaffolds and not further affected by silver coating. Ultrastructural examination and viability assays using either human bone or endothelial cells, demonstrated strong adherence and growth on titanium-only or silver-coated implants. Histological, X-ray computed microtomographic, and ultrastructural analyses revealed that silver-coated titanium scaffolds implanted into 2.5 mm defects in rat tibia promoted robust vascularization and conspicuous bone ingrowth. We conclude that nanolayer silver of titanium implants significantly reduces pathogenic biofilm formation in vitro, facilitates vascularization and osseointegration in vivo making this a promising technique for clinical orthopedic applications.
Collapse
Affiliation(s)
- Aine Devlin-Mullin
- Centre for Molecular Biosciences (CMB); School of Biomedical Sciences; Ulster University; Coleraine BT521SA UK
| | - Naomi M. Todd
- Centre for Molecular Biosciences (CMB); School of Biomedical Sciences; Ulster University; Coleraine BT521SA UK
| | - Zahra Golrokhi
- School of Engineering; University of Liverpool; Liverpool L69 3GH UK
| | - Hua Geng
- School of Materials; The University of Manchester; Oxford Rd Manchester M13 9PL UK
| | - Moritz A. Konerding
- Institute of Functional and Clinical Anatomy; Johannes Gutenberg University; Mainz 55128 Germany
| | - Nigel G. Ternan
- Centre for Molecular Biosciences (CMB); School of Biomedical Sciences; Ulster University; Coleraine BT521SA UK
| | - John A. Hunt
- Institute of Ageing and Chronic Disease; University of Liverpool; Liverpool L7 8TX UK
| | - Richard J. Potter
- School of Engineering; University of Liverpool; Liverpool L69 3GH UK
| | - Chris Sutcliffe
- School of Engineering; University of Liverpool; Liverpool L69 3GH UK
| | - Eric Jones
- School of Engineering; University of Liverpool; Liverpool L69 3GH UK
| | - Peter D. Lee
- School of Materials; The University of Manchester; Oxford Rd Manchester M13 9PL UK
| | - Christopher A. Mitchell
- Centre for Molecular Biosciences (CMB); School of Biomedical Sciences; Ulster University; Coleraine BT521SA UK
| |
Collapse
|
5
|
Mishra S, Daniele S. Metal-Organic Derivatives with Fluorinated Ligands as Precursors for Inorganic Nanomaterials. Chem Rev 2015; 115:8379-448. [PMID: 26186083 DOI: 10.1021/cr400637c] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Shashank Mishra
- Institut de Recherches sur la Catalyse et l'Environnement de Lyon (IRCELYON), UMR 5256, Université Claude Bernard Lyon1 , 2 avenue Albert Einstein, 69626 Villeurbanne, France
| | - Stéphane Daniele
- Institut de Recherches sur la Catalyse et l'Environnement de Lyon (IRCELYON), UMR 5256, Université Claude Bernard Lyon1 , 2 avenue Albert Einstein, 69626 Villeurbanne, France
| |
Collapse
|
6
|
Devi A. ‘Old Chemistries’ for new applications: Perspectives for development of precursors for MOCVD and ALD applications. Coord Chem Rev 2013. [DOI: 10.1016/j.ccr.2013.07.025] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
7
|
Hansen PA, Fjellvåg H, Finstad T, Nilsen O. Structural and optical properties of lanthanide oxides grown by atomic layer deposition (Ln = Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb). Dalton Trans 2013; 42:10778-85. [PMID: 23774891 DOI: 10.1039/c3dt51270c] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ln2O3 thin films with optically active f-electrons (Ln = Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb) have been grown on Si(100) and soda lime glass substrates by atomic layer deposition (ALD) using Ln(thd)3 (Hthd = 2,2,6,6-tetramethyl-3,5-heptanedione) and ozone as precursors. The temperature range for depositions was 200-400 °C. Growth rates were measured by spectroscopic ellipsometry and a region with a constant growth rate (ALD window) was found for Ln = Ho and Tm. All the compounds are grown as amorphous films at low temperatures, whereas crystalline films (cubic C-Ln2O3) are obtained above a certain temperature ranging from 300 to 250 °C for Nd2O3 to Yb2O3, respectively. AFM studies show that the films were smooth (rms < 1 nm) except for depositions at the highest temperatures. The refractive index was measured by spectroscopic ellipsometry and was found to depend on the deposition temperature. Optical absorption measurements show that the absorption from the f-f transitions depends strongly on the crystallinity of the material. The clear correlation between the degree of crystallinity, optical absorptions and refractive indices is discussed.
Collapse
Affiliation(s)
- Per-Anders Hansen
- Department of Chemistry, Centre for Materials Science and Nanotechnology, University of Oslo, Sem Sælandsvei 26, 0371 Oslo, Norway.
| | | | | | | |
Collapse
|
8
|
Daly SR, Kim DY, Girolami GS. Lanthanide N,N-Dimethylaminodiboranates as a New Class of Highly Volatile Chemical Vapor Deposition Precursors. Inorg Chem 2012; 51:7050-65. [DOI: 10.1021/ic201852j] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Scott R. Daly
- The School of Chemical Sciences, University of Illinois at Urbana−Champaign, 600 South Mathews
Avenue, Urbana, Illinois 61801, United States
| | - Do Young Kim
- The School of Chemical Sciences, University of Illinois at Urbana−Champaign, 600 South Mathews
Avenue, Urbana, Illinois 61801, United States
| | - Gregory S. Girolami
- The School of Chemical Sciences, University of Illinois at Urbana−Champaign, 600 South Mathews
Avenue, Urbana, Illinois 61801, United States
| |
Collapse
|
9
|
Zhao CZ, Werner M, Taylor S, Chalker PR, Jones AC, Zhao C. Dielectric Relaxation of La-Doped Zirconia Caused by Annealing Ambient. NANOSCALE RESEARCH LETTERS 2011; 6:48. [PMID: 27502670 PMCID: PMC3211993 DOI: 10.1007/s11671-010-9782-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Accepted: 09/09/2010] [Indexed: 05/30/2023]
Abstract
La-doped zirconia films, deposited by ALD at 300°C, were found to be amorphous with dielectric constants (k-values) up to 19. A tetragonal or cubic phase was induced by post-deposition annealing (PDA) at 900°C in both nitrogen and air. Higher k-values (~32) were measured following PDA in air, but not after PDA in nitrogen. However, a significant dielectric relaxation was observed in the air-annealed film, and this is attributed to the formation of nano-crystallites. The relaxation behavior was modeled using the Curie-von Schweidler (CS) and Havriliak-Negami (HN) relationships. The k-value of the as-deposited films clearly shows a mixed CS and HN dependence on frequency. The CS dependence vanished after annealing in air, while the HN dependence disappeared after annealing in nitrogen.
Collapse
Affiliation(s)
- C Z Zhao
- Department of Electrical and Electronic Engineering, Xi'an Jiaotong, Liverpool University, 215123, Suzhou, Jiangsu, China.
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK.
| | - M Werner
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
- Department of Engineering, Materials Science and Engineering, University of Liverpool, Liverpool, L69 3GH, UK
| | - S Taylor
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
| | - P R Chalker
- Department of Engineering, Materials Science and Engineering, University of Liverpool, Liverpool, L69 3GH, UK
| | - A C Jones
- Department of Chemistry, University of Liverpool, Liverpool, L69 3ZD, UK
| | - Chun Zhao
- Department of Electrical and Electronic Engineering, Xi'an Jiaotong, Liverpool University, 215123, Suzhou, Jiangsu, China
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
| |
Collapse
|
10
|
Aspinall HC, Bacsa J, Jones AC, Wrench JS, Black K, Chalker PR, King PJ, Marshall P, Werner M, Davies HO, Odedra R. Ce(IV) complexes with donor-functionalized alkoxide ligands: improved precursors for chemical vapor deposition of CeO2. Inorg Chem 2011; 50:11644-52. [PMID: 22017450 DOI: 10.1021/ic201593s] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Thin films of ceria (CeO(2)) have many applications, and their synthesis by liquid-injection MOCVD (metal-organic chemical vapor deposition) or ALD (atomic layer deposition) requires volatile precursor compounds. Here we report the synthesis of a series of homoleptic and heteroleptic Ce(IV) complexes with donor-functionalized alkoxide ligands mmp (1-methoxy-2-methylpropan-2-olate), dmap (1-(dimethylamino)propan-2-olate), and dmop (2-(4,4-dimethyl-4,5-dihydrooxazol-2-yl)propan-2-olate) and their potential as precursors for MOCVD and ALD of CeO(2). New complexes were synthesized by alcohol exchange reactions with [Ce(OBu(t))(4)]. [Ce(mmp)(4)] and [Ce(dmap)(4)] were both found to be excellent precursors for liquid-injection MOCVD of CeO(2), depositing high purity thin films with very low carbon contamination, and both have a large temperature window for diffusion controlled growth (350-600 °C for [Ce(mmp)(4)]; 300-600 °C for [Ce(dmap)(4)]). [Ce(mmp)(4)] is also an excellent precursor for liquid-injection ALD of CeO(2) using H(2)O as oxygen source and demonstrates self-limiting growth from 150 to 350 °C. [Ce(dmap)(4)] has lower thermal stability than [Ce(mmp)(4)] and does not show self-limiting growth in ALD. Heteroleptic complexes show a tendency to undergo ligand redistribution reactions to form mixtures in solution and are unsuitable as precursors for liquid-injection CVD.
Collapse
Affiliation(s)
- Helen C Aspinall
- Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, Crown Street, Liverpool, L69 7ZD, UK.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Ashraf S, Jones AC, Bacsa J, Steiner A, Chalker PR, Beahan P, Hindley S, Odedra R, Williams PA, Heys PN. MOCVD of Vertically Aligned ZnO Nanowires Using Bidentate Ether Adducts of Dimethylzinc. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/cvde.201006881] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
12
|
Chalker PR, Romani S, Marshall PA, Rosseinsky MJ, Rushworth S, Williams PA. Liquid injection atomic layer deposition of silver nanoparticles. NANOTECHNOLOGY 2010; 21:405602. [PMID: 20829564 DOI: 10.1088/0957-4484/21/40/405602] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Silver nanoparticles are being developed for applications in plasmonics, catalysts and analytical methods, amongst others. Herein, we demonstrate the growth of silver nanoparticles using an atomic layer deposition (ALD) process for the first time. The silver was deposited from pulses of the organometallic precursor (hfac)Ag(1,5-COD) ((hexafluoroacetylacetonato)silver(I)(1,5-cyclooctadiene)) dissolved in a 0.1 M toluene solution. Catalytic oxidative dehydrogenation of the silver was achieved using intermittent pulses of propanol. The effect of substrate temperature on the size and distribution of nanoparticles has been investigated over the temperature range 110-150 degrees C. Transmission electron microscopy reveals that the nanoparticles consist of face centred cubic, facetted silver crystallites. The localized surface plasmon modes of the nanoparticles have been investigated using electron energy loss spectroscopy mapping. The distributions of plasmons within the ALD nanoparticles are comparable to those grown by solution methods. Both dipolar and quadrupolar resonant modes are observed, which is consistent with previous discrete dipole approximation models. Energy loss mapping of a loss feature at 8.1 eV reveals that it correlates with the bulk or volume region of the silver nanoparticles investigated here.
Collapse
Affiliation(s)
- P R Chalker
- Department of Materials Science and Engineering, University of Liverpool, Liverpool, UK.
| | | | | | | | | | | |
Collapse
|
13
|
Adelmann C, Pierreux D, Swerts J, Dewulf D, Hardy A, Tielens H, Franquet A, Brijs B, Moussa A, Conard T, Van Bael MK, Maes JW, Jurczak M, Kittl JA, Van Elshocht S. Atomic Layer Deposition of Gadolinium Aluminate using Gd(iPrCp)3, TMA, and O3 or H2O. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/cvde.200906833] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
14
|
Black K, Chalker PR, Jones AC, King PJ, Roberts JL, Heys PN. A New Method for the Growth of Zinc Oxide Nanowires by MOCVD using Oxygen-Donor Adducts of Dimethylzinc. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/cvde.200906831] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
15
|
Black K, Jones AC, Bacsa J, Chalker PR, Marshall PA, Davies HO, Heys PN, O'Brien P, Afzaal M, Raftery J, Critchlow GW. Investigation of New 2,5-Dimethylpyrrolyl Titanium Alkylamide and Alkoxide Complexes as Precursors for the Liquid Injection MOCVD of TiO2. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/cvde.200906818] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
16
|
Black K, Jones AC, Alexandrou I, Heys PN, Chalker PR. The optical properties of vertically aligned ZnO nanowires deposited using a dimethylzinc adduct. NANOTECHNOLOGY 2010; 21:045701. [PMID: 20009167 DOI: 10.1088/0957-4484/21/4/045701] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The optical properties of zinc oxide nanowires are critically influenced by the growth process. Herein, we describe a metal-organic chemical vapour deposition (MOCVD) process for the growth of ZnO nanowires with improved optical properties. A tetrahydrofuran adduct is used to control the reactivity of dimethylzinc to enable this. Vertically aligned zinc oxide nanowires have been grown on Si(111) substrates by liquid injection MOCVD, using a solution of [Me(2)Zn(tetrahydrofuran)] in the presence of oxygen. The ZnO morphology becomes nanowire-like in a narrow temperature range centred about 500 degrees C. Above and below this temperature range, the ZnO is deposited in the form of polycrystalline films. The ZnO nanowires grow from a polycrystalline nucleation layer, with the (0002) c-axis parallel to the Si[111] substrate orientation. High-resolution electron microscopy reveals a highly crystalline nanowire microstructure. Resonance enhanced ultraviolet Raman spectroscopy shows that the ratio of first- and second-order longitudinal optic modes is commensurate with electron-phonon coupling effects observed previously in ZnO nanostructures. Photoluminescence exhibits intense near band-edge emission with a full width at half-maximum of 110 meV at room temperature and shows negligible defect-related visible emission.
Collapse
Affiliation(s)
- K Black
- Department of Chemistry, University of Liverpool, Liverpool, UK
| | | | | | | | | |
Collapse
|
17
|
|
18
|
Frequency dispersion and dielectric relaxation of La[sub 2]Hf[sub 2]O[sub 7]. ACTA ACUST UNITED AC 2009. [DOI: 10.1116/1.3043535] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
19
|
Dezelah CL, Niinistö J, Kukli K, Munnik F, Lu J, Ritala M, Leskelä M, Niinistö L. The Atomic Layer Deposition of HfO2and ZrO2using Advanced Metallocene Precursors and H2O as the Oxygen Source. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/cvde.200806716] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
20
|
Black K, Aspinall HC, Jones AC, Przybylak K, Bacsa J, Chalker PR, Taylor S, Zhao CZ, Elliott SD, Zydor A, Heys PN. Deposition of ZrO2 and HfO2 thin films by liquid injection MOCVD and ALD using ansa-metallocene zirconium and hafnium precursors. ACTA ACUST UNITED AC 2008. [DOI: 10.1039/b807205a] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
21
|
Gaskell J, Jones A, Chalker P, Werner M, Aspinall H, Taylor S, Taechakumput P, Heys P. Deposition of Lanthanum Zirconium Oxide High-k Films by Liquid Injection ALD and MOCVD. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/cvde.200706637] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
22
|
O'Kane R, Gaskell J, Jones A, Chalker P, Black K, Werner M, Taechakumput P, Taylor S, Heys P, Odedra R. Growth of HfO2 by Liquid Injection MOCVD and ALD Using New Hafnium-Cyclopentadienyl Precursors. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/cvde.200706589] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
23
|
Aspinall HC, Bickley JF, Gaskell JM, Jones AC, Labat G, Chalker PR, Williams PA. Precursors for MOCVD and ALD of Rare Earth Oxides−Complexes of the Early Lanthanides with a Donor-Functionalized Alkoxide Ligand. Inorg Chem 2007; 46:5852-60. [PMID: 17580930 DOI: 10.1021/ic061382y] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Complexes of the early lanthanides with the donor-functionalized alkoxide ligand mmp (Hmmp = HOCMe(2)CH(2)OMe, 1-methoxy-2-methylpropan-2-ol) are excellent precursors for Metal Organic Chemical Vapor Deposition (MOCVD) and Atomic Layer Deposition (ALD) of lanthanide oxides; however, their coordination chemistry, which is the subject of this paper, is rather complex. Precursors for MOCVD and ALD of lanthanide oxides are prepared by the reaction of [Ln{N(SiMe(3))(2)}(3)] with 3 equiv of the alcohol Hmmp in toluene in the presence of 1 equiv of tetraglyme and are indefinitely stable in solution. Reaction of [Ln{N(SiMe(3))(2)}(3)] with 3 equiv of Hmmp in the absence of stabilizing Lewis bases gives complex condensed products with empirical formula [{Ln(mmp)(3-n)}(2)O(n)]. These condensed products show poor volatility and are unsatisfactory precursors for MOCVD or ALD of oxides. The cluster complex [La(3)(mu(3),kappa(2)-mmp)(2)(mu(2),kappa(2)-mmp)(3)(mmp)(4)] has been prepared by careful reaction of [La{N(SiMe(3))(2)}(3)] with 4 equiv of Hmmp and has been characterized by single-crystal X-ray diffraction. Salt metathesis reactions using M(mmp) (M = Li or Na) are unreliable routes to [Ln(mmp)(3)]. Crystals of the heterometallic cluster complex [NaLa(3)(mu(3)-OH)(mu(3),kappa(2)-mmp)(2)(mu(2),kappa(2)-mmp)(4)(mmp)(3)] were isolated from the reaction of [La(NO(3))(3)(tetraglyme)] with 3 equiv of Na(mmp), and crystals of [Li(kappa(2)-Hmmp)Pr(mu(2),eta(2)-mmp)(4))LiCl] were isolated from the reaction of PrCl(3) with 3 equiv of Li(mmp); both of these complexes have been characterized by single-crystal X-ray diffraction.
Collapse
Affiliation(s)
- Helen C Aspinall
- Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK.
| | | | | | | | | | | | | |
Collapse
|
24
|
Milanov A, Bhakta R, Baunemann A, Becker HW, Thomas R, Ehrhart P, Winter M, Devi A. Guanidinate-Stabilized Monomeric Hafnium Amide Complexes as Promising Precursors for MOCVD of HfO2. Inorg Chem 2006; 45:11008-18. [PMID: 17173460 DOI: 10.1021/ic061056i] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Novel guanidinato complexes of hafnium [Hf{eta2-(iPrN)2CNR2}2(NR2)2] (R2 = Et2, 1; Et, Me, 2; Me2, 3), synthesized by insertion reactions of N,N'-diisopropylcarbodiimide into the M-N bonds of homologous hafnium amide complexes 1-3 and {[mu2-NC(NMe2)2][NC(NMe2)2]2HfCl}2 (4) using a salt metathesis reaction, are reported. Single-crystal X-ray diffraction analysis revealed that compounds 1-3 were monomers, while compound 4 was found to be a dimer. The observed fluxional behavior of compounds 1-3 was studied in detail using variable-temperature and two-dimensional NMR techniques. The thermal characteristics of compounds 1-3 seem promising for HfO2 thin films by vapor deposition techniques. Metal-organic chemical vapor deposition experiments with compound 2 as the precursor resulted in smooth, uniform, and stoichiometric HfO2 thin films at relatively low deposition temperatures. The basic properties of HfO2 thin films were characterized in some detail.
Collapse
Affiliation(s)
- Andrian Milanov
- Inorganic Materials Chemistry Group, Lehrstuhl für Anorganische Chemie II, Ruhr-University Bochum, D-44780 Bochum, Germany
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Cho W, An KS, Chung TM, Kim C, So BS, You YH, Hwang JH, Jung D, Kim Y. ALD of Hafnium Dioxide Thin Films Using the New Alkoxide Precursor Hafnium 3-Methyl-3-pentoxide, Hf(mp)4. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/cvde.200506458] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
26
|
Jones A, Aspinall H, Chalker P, Potter R, Manning T, Loo Y, O'Kane R, Gaskell J, Smith L. MOCVD and ALD of High-k Dielectric Oxides Using Alkoxide Precursors. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/cvde.200500023] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
27
|
Schumacher M, Baumann P, Seidel T. AVD and ALD as Two Complementary Technology Solutions for Next Generation Dielectric and Conductive Thin-Film Processing. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/cvde.200500027] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
28
|
Gaskell JM, Jones AC, Aspinall HC, Przybylak S, Chalker PR, Black K, Davies HO, Taechakumput P, Taylor S, Critchlow GW. Liquid injection ALD and MOCVD of lanthanum aluminate using a bimetallic alkoxide precursor. ACTA ACUST UNITED AC 2006. [DOI: 10.1039/b609129f] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
29
|
Sebe E, Guzei IA, Heeg MJ, Liable-Sands LM, Rheingold AL, Winter CH. Synthesis, Structure, and Properties of Zirconium and Hafnium Complexes Containing η2-Pyrazolato Ligands. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200500378] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
30
|
Päiväsaari J, Dezelah, IV CL, Back D, El-Kaderi HM, Heeg MJ, Putkonen M, Niinistö L, Winter CH. Synthesis, structure and properties of volatile lanthanide complexes containing amidinate ligands: application for Er2O3 thin film growth by atomic layer deposition. ACTA ACUST UNITED AC 2005. [DOI: 10.1039/b507351k] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|