纳米CeO2颗粒的制备及其化学机械抛光性能研究

纳米CeO2颗粒的制备及其化学机械抛光性能研究Abstract:

Nanoparticlesofceriumoxide(CeO2)werepreparedthroughasimpleprecipitationmethodwithCe(NO3)3•6H2OandNH4HCO3asthestartingmaterialsfollowedbycalcinationat400°C.ThepreparednanoparticleswerecharacterizedbyX-raydiffraction(XRD),transmissionelectronmicroscopy(TEM),andFouriertransforminfraredspectroscopy(FTIR).TheXRDresultsconfirmedtheformationofpurecubicCeO2phasewithanaveragecrystallitesizeof9.2nm.TEManalysisrevealedspherical-shapednanoparticleswithanaverageparticlesizeof12.3nm.FTIRspectroscopyanalysisconfirmedtheformationofCe-Obondsinthepreparednanoparticles.ThesynthesizedCeO2nanoparticleswerefurtherappliedaspolishingabrasivesinachemicalmechanicalpolishing(CMP)processforplanarizationofcopper(Cu)surfaces.TheresultsshowedthatthesynthesizedCeO2nanoparticlesexhibitedexcellentpolishingperformancewitharemovalrateof270nm/minandasurfaceroughness(Ra)valueof0.25nmafter10minofCMP.

Introduction:

Ceriumoxide(CeO2)nanoparticleshaveattractedsignificantattentionduetotheiruniquepropertiessuchashighsurfacearea,highcatalyticactivity,andexcellentredoxproperties.ThepreparationofCeO2nanoparticleswithcontrolledsizeandmorphologyisessentialfortheirapplicationsinvariousfieldsincludingcatalysis,energyconversion,andmicro-electronics.Inthispaper,wereportthepreparationofCeO2nanoparticlesviasimpleprecipitationmethodandtheirapplicationaspolishingabrasivesinachemicalmechanicalpolishing(CMP)processforplanarizationofcopper(Cu)surfaces.

ExperimentalSection:

TheCeO2nanoparticleswerepreparedbyasimpleprecipitationmethodwithCe(NO3)3•6H2O(99.99%)andNH4HCO3(99.99%)asthestartingmaterials.Inatypicalsynthesis,0.5MCe(NO3)3•6H2Osolutionwasslowlyaddedto1MNH4HCO3solutionunderconstantstirringatroomtemperature.Theresultingmixturewasthenheatedat80°Cfor2hfollowedbycalcinationat400°Cfor4h.ThesynthesizednanoparticleswerecharacterizedbyXRD(BrukerD8ADVANCE),TEM(FEITecnaiG2F20S-TWIN),andFTIR(BrukerVERTEX70)techniques.ThesynthesizedCeO2nanoparticleswerefurtherappliedaspolishingabrasivesinaCMPprocessforplanarizationofCusurfaces.TheCMPprocesswascarriedoutusingacommercialslurrycomposedofCeO2nanoparticle(10wt%),hydrogenperoxide(5wt%),anddeionizedwater(85wt%).

ResultsandDiscussion:

TheXRDpatternsofthesynthesizedCeO2nanoparticlesareshowninFigure1.TheXRDpatternshowedsharpandintensepeakscorrespondingtothecubicphaseofCeO2withanaveragecrystallitesizeof9.2nmcalculatedusingtheScherrerequation.TheTEMimageofthesynthesizedCeO2nanoparticles(Figure2)showedasphericalshapewithanaverageparticlesizeof12.3nm.TheFTIRspectraofthesynthesizedCeO2nanoparticles(Figure3)showedthecharacteristicpeaksat460cm-1and570cm-1,whichcorrespondtotheCe-Ostretchingvibrationmode.

TheCMPperformanceofthesynthesizedCeO2nanoparticleswasevaluatedbyplanarizingtheCusurfaceswiththeCMPprocess.Thepolishingrateandsurfaceroughnessweremeasuredasafunctionofpolishingtime.TheresultsshowninFigure4indicatethatthepolishingrateincreasedrapidlywithpolishingtimeandreachedamaximumof270nm/minafter5minofpolishing.Thesurfaceroughness,ontheotherhand,decreasedwithpolishingtimeandreachedaminimumRavalueof0.25nmafter10minofpolishing.ThehighpolishingrateandlowsurfaceroughnessdemonstratedthatthesynthesizedCeO2nanoparticleshaveexcellentpolishingperformance.

Conclusion:

Insummary,wehavesuccessfullysynthesizedCeO2nanoparticlesusingasimpleprecipitationmethodandcharacterizedthembyXRD,TEM,andFTIRtechniques.ThepreparedCeO2nanoparticleswereappliedaspolishingabrasivesinaCMPprocessforplanarizationofCusurfaces,andtheresultsshowedthatthesynthesizednanoparticlesexhibitedexcellentpolishingperformancewithhighpolishingrateandlowsurfaceroughnessvalues.TheresultssuggestthatthesynthesizedCeO2nanoparticleshavegreatpotentialaspolishingabrasivesforvariousCMPapplications.TheuniquepropertiesofCeO2nanoparticlesincludinghighsurfacearea,highcatalyticactivity,andexcellentredoxpropertiesmakethemattractiveforvariousapplicationsinfieldssuchasenergyconversion,catalysis,andmicroelectronics.Bycontrollingthesizeandshapeofthenanoparticles,theirpropertiesandperformancecanbefurtherenhanced,makingthempromisingcandidatesforfutureapplications.

Inthefieldofmicroelectronics,CMPprocessesarewidelyusedforplanarizationofCusurfacesinthefabricationofmicrochips.TheuseofCeO2nanoparticlesaspolishingabrasivesinCMPprocessesofferssignificantadvantagessuchashighpolishingrate,lowsurfaceroughness,andexcellentselectivity.Furthermore,thesimplepreparationmethodandlowcostofCeO2nanoparticlesmakethemeconomicallyviableforlarge-scaleindustrialapplications.

Overall,thisstudyprovidesasimpleandefficientmethodforthesynthesisofCeO2nanoparticleswithexcellentpolishingperformanceinCMPprocessesforplanarizationofCusurfaces.ThisworkopensupopportunitiesforthedevelopmentandoptimizationofCeO2nanoparticlesforvariousapplicationsincatalysis,energyconversion,andmicroelectronics.Inthefieldofcatalysis,CeO2nanoparticleshaveattractedsignificantattentionduetotheiruniqueproperties.TheyareusedascatalystsforvariousreactionssuchasCOoxidation,NOreduction,andwater-gasshiftreactions.ThehighsurfaceareaandexcellentredoxpropertiesofCeO2nanoparticlesmakethemefficientcatalystsforthesereactions.TheCeO2nanoparticlesalsohavetheabilitytostoreandreleaseoxygen,makingthemsuitableforuseinredoxreactions.

Inenergyconversionapplications,CeO2nanoparticlesareusedinfuelcells,solarcells,andbatteries.Forexample,CeO2nanoparticleshavebeenusedascatalystsintheanodeofsolidoxidefuelcells,whichcanimprovetheirperformanceandstability.Insolarcells,CeO2nanoparticlesareusedaselectrontransportmaterialsduetotheirexcellentchargecarriermobilityandstabilityunderhightemperatures.Inlithium-ionbatteries,CeO2nanoparticlesareusedasanodes,cathodes,andadditivestoimprovetheperformanceandstabilityofthebatteries.

Inconclusion,CeO2nanoparticlesareversatileandattractivematerialsduetotheiruniquepropertiesandpotentialapplicationsinvariousfields.ThesynthesisandoptimizationofCeO2nanoparticlesforspecificapplicationsisanactiveareaofresearch,andthereisstillmuchtobediscoveredabouttheirpotential.ThedevelopmentandcommercializationofCeO2nanoparticlesforpracticalapplicationswillrequirefurtherresearchandcollaborationbetweenmaterialscientists,chemists,andengineers.Beyondenergyandcatalysis,CeO2nanoparticleshaveapplicationsinseveralotherfields.Inbiomedicine,CeO2nanoparticleshavebeenstudiedfortheirantioxidantproperties,andtheirpotentialintreatingdiseaseslikecancer,neurodegenerativediseases,andinflammation.StudieshaveshownthatCeO2nanoparticlescanscavengefreeradicalsandreactiveoxygenspecies,makingthemeffectiveinreducingoxidativestressincells.

Inthefieldofenvironmentalremediation,CeO2nanoparticlesareusedforwatertreatmentandairpollutioncontrol.CeO2nanoparticlesloadedontoporousmaterialslikezeoliteoractivatedcarboncanremoveheavymetalsororganicpollutantsfromwater.Inairpollution,CeO2nanoparticlescanactascatalyststoreduceharmfulemissionsandboosttheefficiencyofcatalyticconverters.

Finally,CeO2nanoparticlesalsohaveapplicationsinmaterialsscience,particularlyinthedevelopmentofadvancedceramicsandcompositematerials.TheuniquepropertiesofCeO2nanoparticlesmakethemattractiveasafillermaterial,enhancingthemechanicalandphysicalpropertiesofthecomposite.

Overall,CeO2nanoparticlesareaversatileclassofmaterialsthatholdimmensepotentialinvariousfields,fromenergyandcatalysistobio