原子层沉积法的原理和应用

AtomicLayerDeposition(ALD)

杨超、包峰、方聪、蒋博瀚、马红石李勇辉、王谦、徐晨、于浩、赵灿灿

—ShanghaiInstituteofCeramicsSyntheticChemistryofMaterialsOutlineOutline1.IntroductiontoALD2.Classicalmodels:ALDofAl2O33.ALDandCVD4.ApplicationsofALD(1)Coatingsonhighaspectratiostructures(2)CoatingsonNanoparticles(3)CombinationofCNT(4)PlasmaALD5.ExpectationsandchallengeinALD2.Classicalmodels:ALDofAl2O3TheoverallreactionforAl2O3ALD

2Al(CH3)3+3H2OAl2O3+3CH4∆H=376kcal

ThesurfacechemistryduringAl2O3ALD

(a)AlOH*+Al(CH3)3AlOAl(CH3)2*+CH4

(b)AlCH3*+H2OAlOH*+CH4

Characters5Highrepeatabilityandexpansibility6Substrate（Large

andhighaspectratio）4Pinhole-freefilms3Conformaldeposition2Self-limiting1Atomiclevelcontrol1.IntroductiontoALDAtomiclayerdeposition（ALD）

—atomiclevelcontroloffilmdeposition3.ComparisonofALDandCVDSchematicpressureprofileduringtheALDandCVDprocessSeung-MoLeeetal.,ChemPhysChem,12,791-798(2011)3.ComparisonofALDandCVDSequentialintroductionofprecursorsSynchronousintroductionofprecursorsALDCVDBetterstepcoverageExistingshadowingeffectsAtomiclevelcontrolIcan’t12M.Knaut,etal.MicroelectronEng,107,80-83(2013)4.1CoatingsonhighaspectratiostructuresCoatingonstep-likesructures1Coatingonmulti-porestructures24.2CoatingsonnanoparticlesPSspheresselfassembledALDofTiCl4andH2OIonmillingEtching

PS

hemispheresAnnealingXuDongWangetal.,NanolettersVol.4,No.11(2004)4.2CoatingsonnanoparticlesALD

Cycles→Bowl

ThicknessPSSpheres→BowlSize4.3CombinationofCNTandsuper-blackcoatingsSchematicillustrationoftheALDandCVDprocessforthesynthesisofCNTarraysSchematicrepresentationofAl2O3ALDcoatingonmonodispersedNPs.4.3CombinationofCNTandsuper-blackcoatingsKaiZhou,etal.,NanoscaleResLett,

5:1555-1560(2010)XinWang,etal.,ACSAppl.Mater.Interfaces,3:4180-4184(2011)Improvedmaterialpropertiesfilmdensity,impuritycontent,electronicpropertiesDepositionatreducedsubstratetemperaturesIncreasedchoiceofprecursorsandmaterialsGoodcontrolofstoichiometryandcompositionoperatingpressure,power,exposuretime,biasingvoltageIncreasedgrowthrate4.4MeritsofPlasma-AssistedALDN.Leick,J.Vac.Sci.Technol.A29,021016(2011)Meritsb.DirectplasmaALDc.RemoteplasmaALDd.Directplasmareactorwithmesha.Radical-enhancedALD4.4Plasma-AssistedALDConfigurationsAssistinganALDprocessbymeansofaplasmastep:FigVariousreactorconfigurationsforplasma-assistedALDN.Leick,J.Vac.Sci.Technol.A29,021016(2011)StevenM.George,ChemicalReviews,110,111-131(2010)ChallengesControllingthedosagesDifferentmulti-metaldepositionDifferentoxidedopeddepositionDecomposingReasonablevaporpressureReactionisbetweentheprecursorsandthematrixesAppliedtothemassproductionLowdepositionrate100-300nm/h2.Chemicalrequirements1.Lowdepositionrate3.Complexity5.1ChallengesofALD

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