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1、FabricationandCharacterizationofNanomaterialsJohnCarruthersPhysicsDepartmentPortlandStateUniversityJune26,20069/16/20211JohnCarruthers,PortlandStateUniversityFabricationandCharacterizationofNanomaterials OutlineofOpeningLectureWhyphysicschangesatthenanoscaleExamplesofnanoscaled
2、evices,circuits,andsystemsGeneralsemiconductorICfabricationmethodsandlimitationsNeedformetrologiestosupportsemiconductorfabrication,performanceevaluation,failureanalysis,andreliabilityassessmentTypesofmetrologiesWrapupandfuturechallenges9/16/20212JohnCarruthers,PortlandStateUni
3、versity9/16/20213JohnCarruthers,PortlandStateUniversityWhyphysicschangesatthenanoscaleSurfacearea/volumeratioincreasesas1/Randthesurfacesandinterfacesbecomethemajorcontributortomaterialsproperties,thermodynamicbehavior,andenergycarrierdynamicsatthenanoscaleDiffusionofatomstosur
4、facesandinterfaceschangesthethermodynamicequilibriumconditionsSolidtransportofheat,matter,chargecarriers,photons,--allchangeatthenanoscalebecausethescatteringcentersarespacedfurtherapartthanthenanoscaledimensionsElectronicdensityofstatesbecomesdiscontinuouswhendimensionsareredu
5、cedtoquantumwells,quantumwires,andquantumdots.Thisleadstonewphysicalconceptssuchasenergyfiltering,carrier“pocketengineering”,andelectronictransitions(suchassemimetal-semiconductortransitions)Size-dependentenergylevelsduetoquantumconfinementchangetheenergeticsofdopingsemiconduct
6、ornanocrystalsFluidtransportinnanoscalechannelscanbeenhancedbyatomicsmoothness,contactanglechanges,andmolecularorderingofthemoleculesbeingtransported9/16/20214JohnCarruthers,PortlandStateUniversityWhyphysicschangesatthenanoscaleTerascalesemiconductordevicedensitiesleadtonewnano
7、scaleproblems:OverlapofelectricfieldscausesthresholdvoltageloweringindevicesandparasiticsignaltransferininterconnectsTunnelinginducedleakagecausesexcessivechargelossacrossverythindielectrics(increasesexponentiallyas1/thickness)Excessiveheatgenerationduetotheinherentswitchingene
8、rgygovernedbythermodynamics(~100kTln2=1.7eV/switchatR.
