0000000000133088

AUTHOR

Jani Hämäläinen

0000-0002-2903-1199

showing 4 related works from this author

Iridium metal and iridium oxide thin films grown by atomic layer deposition at low temperatures

2011

Atomic layer deposition (ALD) of both iridium and iridium oxide films at low temperatures has been studied and the resulting films have been examined by XRD, FESEM, XRR, EDX, AFM, TOF-ERDA, and four point probe measurements. Iridium oxide films were successfully grown using (MeCp)Ir(CHD) and ozone between 100 and 180 °C, however, the density of the films substantially reduced at 120 °C and below. The density reduction was accompanied by a phase change from crystalline to amorphous IrO2. Metallic iridium films were deposited between 120 and 180 °C by adding a reductive hydrogen pulse after the oxidative ozone pulse. Comparison of these processes with the earlier process employing the same Ir…

Materials scienceHydrogenta114Inorganic chemistrychemistry.chemical_element02 engineering and technologyGeneral Chemistry010402 general chemistry021001 nanoscience & nanotechnology01 natural sciencesOxygen0104 chemical sciencesAmorphous solidX-ray reflectivityMetalAtomic layer depositionchemistryvisual_artMaterials Chemistryvisual_art.visual_art_mediumIridiumThin film0210 nano-technologyta116Journal of Materials Chemistry
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Low temperature atomic layer deposition of noble metals using ozone and molecular hydrogen as reactants

2013

Abstract Atomic layer deposition (ALD) of noble metals by thermal processes has relied mostly on the use of molecular oxygen as a reactant at temperatures of 200 °C and above. In this study, the concept of using consecutive ozone and molecular hydrogen pulses with noble metal precursors in ALD is introduced for palladium, rhodium, and platinum metals. This approach facilitates the growth of noble metal thin films below 200 °C. Also the ALD of palladium oxide thin films is demonstrated by the ozone-based chemistry. The growth rates, resistivities, crystallinities, surface roughnesses, impurity contents, and adhesion of the films to the underlying Al 2 O 3 starting surface are reported and th…

OzoneInorganic chemistrychemistry.chemical_element02 engineering and technologyengineering.material010402 general chemistry01 natural sciencesRhodiumAtomic layer depositionchemistry.chemical_compoundImpurityMaterials ChemistryThin filmta116ta114Metals and AlloysSurfaces and Interfaces021001 nanoscience & nanotechnology0104 chemical sciencesSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialschemistryengineeringNoble metal0210 nano-technologyPlatinumPalladiumThin Solid Films
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Atomic Layer Deposition of LiF Thin Films from Lithd, Mg(thd)2, and TiF4 Precursors

2013

Lithium fluoride is an interesting material because of its low refractive index and large band gap. Previously LiF thin films have been deposited mostly by physical methods. In this study a new way of depositing thin films of LiF using atomic layer deposition (ALD) is presented. Mg(thd)2, TiF4 and Lithd were used as precursors, and they produced crystalline LiF at a temperature range of 300–350 °C. The films were studied by UV–vis spectrometry, field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), atomic force microscopy (AFM), time-of-flight elastic recoil detection analysis (ToF-ERDA), and energy dispersive X-ray spectroscopy (EDX). In addition, film adhesion was t…

010302 applied physicsMaterials scienceta214ta114Band gapGeneral Chemical EngineeringAnalytical chemistryLithium fluoride02 engineering and technologyGeneral ChemistryAtmospheric temperature range021001 nanoscience & nanotechnology01 natural sciencesElastic recoil detectionchemistry.chemical_compoundAtomic layer depositionchemistryImpurity0103 physical sciencesMaterials ChemistryThin film0210 nano-technologySpectroscopyChemistry of Materials
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Atomic Layer Deposition of Osmium

2011

Growth of osmium thin films and nanoparticles by atomic layer deposition is described. The Os thin films were successfully grown between 325 and 375 °C using osmocene and molecular oxygen as precursors. The films consisted of only Os metal as osmium oxides were not detected in X-ray diffraction measurements. Also the impurity contents of oxygen, carbon, and hydrogen were less than 1 at % each at all deposition temperatures. The long nucleation delay of the Os process facilitates either Os nanoparticle or thin film deposition. However, after the nucleation delay of about 350 cycles the film growth proceeded linearly with increasing number of deposition cycles. Also conformal growth of Os thi…

010302 applied physicsMaterials scienceta114General Chemical EngineeringInorganic chemistryAnalytical chemistryNucleationchemistry.chemical_element02 engineering and technologyGeneral ChemistryChemical vapor deposition021001 nanoscience & nanotechnologyOsmocene01 natural scienceschemistry.chemical_compoundAtomic layer depositionCarbon filmchemistry0103 physical sciencesMaterials ChemistryDeposition (phase transition)OsmiumThin film0210 nano-technologyta116Chemistry of Materials
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