0000000000076180

AUTHOR

Kaupo Kukli

0000-0002-5821-0364

showing 9 related works from this author

Evaluation and Comparison of Novel Precursors for Atomic Layer Deposition of Nb2O5 Thin Films

2012

Atomic layer deposition (ALD) of Nb2O5 thin films was studied using three novel precursors, namely, tBuN═Nb(NEt2)3, tBuN═Nb(NMeEt)3, and tamylN═Nb(OtBu)3. These precursors are liquid at room temperature, present good volatility, and are reactive toward both water and ozone as the oxygen sources. The deposition temperature was varied from 150 to 375 °C. ALD-type saturative growth modes were confirmed at 275 °C for tBuN═Nb(NEt2)3 and tBuN═Nb(NMeEt)3 together with both oxygen sources. Constant growth rate was observed between a temperature regions of 150 and 325 °C. By contrast, amylN═Nb(OtBu)3 exhibited limited thermal stability and thus a saturative growth mode was not achieved. All films we…

010302 applied physicsMaterials scienceta114General Chemical EngineeringAnalytical chemistrychemistry.chemical_element02 engineering and technologyGeneral Chemistry021001 nanoscience & nanotechnology01 natural sciencesOxygenAmorphous solidElastic recoil detectionAtomic layer depositionchemistry0103 physical sciencesMaterials ChemistryThermal stabilityThin film0210 nano-technologyta116Volatility (chemistry)High-κ dielectricChemistry of Materials
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Atomic Layer Deposition of Ruthenium Films from (Ethylcyclopentadienyl)(pyrrolyl)ruthenium and Oxygen

2011

Ru films were grown by atomic layer deposition in the temperature range of 275―350°C using (ethylcyclopentadienyl)(pyrrolyl)ruthenium and air or oxygen as precursors on HF-etched Si, SiO 2 , ZrO 2 , and TiN substrates. Conformal growth was examined on three-dimensional silicon substrates with 20:1 aspect ratio. ZrO 2 promoted the nucleation of Ru most efficiently compared to other substrates, but the films roughened quickly on ZrO 2 with increasing film thickness. The minimum number of cycles required to form continuous and conductive metal layers could be decreased by increasing the length of the oxygen pulse. In order to obtain well-conducting Ru films growth to thicknesses of at least 8―…

Materials scienceSiliconInorganic chemistryAnalytical chemistryNucleationchemistry.chemical_element02 engineering and technology01 natural sciencesOxygenMetalAtomic layer deposition0103 physical sciencesMaterials ChemistryElectrochemistryta116010302 applied physicsta114Renewable Energy Sustainability and the EnvironmentAtmospheric temperature range021001 nanoscience & nanotechnologyCondensed Matter PhysicsSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsRutheniumchemistryvisual_artvisual_art.visual_art_medium0210 nano-technologyTinJournal of The Electrochemical Society
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Investigation of ZrO[sub 2]–Gd[sub 2]O[sub 3] Based High-k Materials as Capacitor Dielectrics

2010

Atomic layer deposition (ALD) of ZrO 2 ―Gd 2 O 3 nanolaminates and mixtures was investigated for the preparation of a high permittivity dielectric material. Variation in the relative number of ALD cycles for constituent oxides allowed one to obtain films with controlled composition. Pure ZrO 2 films possessed monoclinic and higher permittivity cubic or tetragonal phases, whereas the inclusion of Gd 2 O 3 resulted in the disappearance of the monoclinic phase. Changes in phase composition were accompanied with increased permittivity of mixtures and laminates with low Gd content. Further increase in the lower permittivity Gd 2 O 3 content above 3.4 cat. % resulted in the decreased permittivity…

010302 applied physicsPermittivityMaterials scienceRenewable Energy Sustainability and the EnvironmentAnalytical chemistryEquivalent oxide thickness02 engineering and technologyDielectric021001 nanoscience & nanotechnologyCondensed Matter Physics01 natural sciencesSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsAtomic layer depositionElectric field0103 physical sciencesMaterials ChemistryElectrochemistry0210 nano-technologyCurrent densityLeakage (electronics)High-κ dielectricJournal of The Electrochemical Society
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Atomic layer deposition of Ru films from bis(2,5-dimethylpyrrolyl)ruthenium and oxygen

2012

Abstract Ru thin films were grown on hydrogen terminated Si, SiO 2 , Al 2 O 3 , HfO 2 , and TiO 2 surfaces by atomic layer deposition from bis(2,5-dimethylpyrrolyl)ruthenium precursor and oxygen. The 4–20 nm thick films on these surfaces consisted of nanocrystalline hexagonal metallic ruthenium, regardless of the deposition temperature. At the lowest temperatures examined, 250–255 °C, the growth of the Ru films was favored on silicon, compared to the growth on Al 2 O 3 , TiO 2 and HfO 2 . At higher temperatures the nucleation and growth of Ru became enhanced in particular on HfO 2 , compared to the process on silicon. At 320–325 °C, no growth occurred on Si–H and SiO 2 -covered silicon. Res…

Materials scienceSiliconHydrogenNucleationchemistry.chemical_elementNanotechnology02 engineering and technology01 natural sciencesMetalAtomic layer deposition0103 physical sciencesMaterials ChemistryThin filmta116010302 applied physicsta114Metals and AlloysSurfaces and Interfaces021001 nanoscience & nanotechnologyNanocrystalline materialSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsRutheniumchemistryChemical engineeringvisual_artvisual_art.visual_art_medium0210 nano-technologyThin Solid Films
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Atomic Layer Deposition and Characterization of Erbium Oxide-Doped Zirconium Oxide Thin Films

2010

ZrO 2 films doped with Er 2 O 3 were grown by atomic layer deposition from tris(2,2,6,6-tetramethyl-3,5-heptanedionato)erbium, bis(methylcyclopentadienyl)methoxymethylzirconium, and ozone as precursors at 350°C. The erbium content was 1―5 cation %. The films were uniform in thickness. The ZrO 2 :Er 2 O 3 films were crystallized already in the as-deposited state. Upon annealing at 650°C, they were stabilized in the form of cubic or tetragonal polymorph of ZrO 2 . Enhancement in capacitance required intense crystallization that was observed when the film thickness exceeded 4.4 nm. The permittivity of the ZrO 2 :Er 2 O 3 films could reach 31. The capacitors based on the doped ZrO 2 possessed l…

Materials scienceAnnealing (metallurgy)Inorganic chemistryOxideAnalytical chemistrychemistry.chemical_elementEquivalent oxide thickness02 engineering and technology01 natural scienceslaw.inventionErbiumchemistry.chemical_compoundAtomic layer depositionlaw0103 physical sciencesMaterials ChemistryElectrochemistryThin filmCrystallization010302 applied physicsRenewable Energy Sustainability and the EnvironmentDoping021001 nanoscience & nanotechnologyCondensed Matter PhysicsSurfaces Coatings and FilmsElectronic Optical and Magnetic Materialschemistry0210 nano-technologyJournal of The Electrochemical Society
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Atomic Layer Deposition and Properties of Lanthanum Oxide and Lanthanum-Aluminum Oxide Films

2006

Atomic layer deposition (ALD) of lanthanum oxide on glass and silicon substrates was examined using lanthanum silylamide, La[N(SiMe 3 ) 2 ] 3 , and water as precursors in the substrate temperature range of 150-250 °C. The effect of pulse times and precursor evaporation temperature on the growth rate and refractive index was investigated. The films remained amorphous regardless of the deposition conditions. The resulting La 2 O 3 films contained noticeable amounts of hydrogen and silicon and were chemically unstable while stored in ambient air. Lanthanum aluminum oxide films were achieved with stoichiometry close to that of LaAlO 3 at 225°C from La[N(SiMe 3 ) 2 ] 3 , Al(CH 3 ) 3 , and H 2 O.…

010302 applied physicsLanthanideSiliconProcess Chemistry and TechnologyInorganic chemistrychemistry.chemical_element02 engineering and technologySurfaces and InterfacesGeneral ChemistrySubstrate (electronics)021001 nanoscience & nanotechnology01 natural sciencesEvaporation (deposition)Amorphous solidAtomic layer depositionchemistry.chemical_compoundchemistryLanthanum oxide0103 physical sciencesLanthanum0210 nano-technologyChemical Vapor Deposition
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Properties of atomic layer deposited nanolaminates of zirconium and cobalt oxides

2018

Producción Científica

Materials scienceSilicon116 Chemical sciencesta221chemistry.chemical_element02 engineering and technologyDielectricChemical vapor deposition7. Clean energy01 natural sciencesSpray pyrolysisThermal barrier coatingÓxidos metálicosSPRAY-PYROLYSISDIELECTRICSnanorakenteetmagnetoelectrics0103 physical sciencesNanolaminatesnanolaminatesSILICON010302 applied physicsZirconiumta114ZRO2 THIN-FILMSCO3O4 FILMSBUFFER LAYERatomikerroskasvatus021001 nanoscience & nanotechnologyElectronic Optical and Magnetic MaterialsTHERMAL BARRIER COATINGSCHEMICAL-VAPOR-DEPOSITIONchemistryChemical engineeringLASER DEPOSITIONNanoláminasatomic layer depositionMetal oxides221 Nano-technologyohutkalvot0210 nano-technologyLayer (electronics)CobaltGAS SENSORS
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Mechanical properties of aluminum, zirconium, hafnium and tantalum oxides and their nanolaminates grown by atomic layer deposition

2015

ABSTRACT The mechanical properties of two different metal oxide nanolaminates comprised of Ta 2 O 5 and Al 2 O 3 , HfO 2 or ZrO 2 , grown on soda–lime glass substrate by atomic layer deposition, were investigated. Ta 2 O 5 and Al 2 O 3 layers were amorphous, whereas ZrO 2 and HfO 2 possessed crystalline structure. Thickness of single oxide layers was varied between 2.5 and 15 nm. The total thickness of the laminate structures was in the range of 160–170 nm. The hardness values of single layer oxides on glass ranged from 6.7 GPa (Ta 2 O 5 ) to 9.5 GPa (Al 2 O 3 ). Corresponding elastic moduli were 96 GPa and 101 GPa. The hardnesses of laminates were in the range of 6.8–7.8 GPa and elastic mo…

ZirconiumMaterials scienceMetallurgyTantalumOxidechemistry.chemical_elementSurfaces and InterfacesGeneral ChemistrySubstrate (electronics)Condensed Matter PhysicsSurfaces Coatings and FilmsAmorphous solidAtomic layer depositionchemistry.chemical_compoundchemistryAluminiumMaterials ChemistryComposite materialThin filmSurface and Coatings Technology
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Atomic layer deposition of aluminum oxide on modified steel substrates

2016

Abstract Al 2 O 3 thin films were grown by atomic layer deposition to thicknesses ranging from 10 to 90 nm on flexible steel substrates at 300 °C using Al(CH 3 ) 3 and H 2 O as precursors. The films grown to thicknesses 9–90 nm covered the rough steel surfaces uniformly, allowing reliable evaluation of their dielectric permittivity and electrical current densities with appreciable contact yield. Mechanical behavior of the coatings was evaluated by nanoindentation. The maximum hardness values of the Al 2 O 3 films on steel reached 12 GPa and the elastic modulus exceeded 280 GPa.

010302 applied physicsYield (engineering)Materials scienceMetallurgy02 engineering and technologySurfaces and InterfacesGeneral ChemistryChemical vapor depositionNanoindentation021001 nanoscience & nanotechnologyCondensed Matter Physics01 natural sciencesSurfaces Coatings and FilmsAtomic layer deposition0103 physical sciencesMaterials ChemistrySurface modificationThin filmComposite material0210 nano-technologyElastic modulusAluminum oxideSurface and Coatings Technology
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