第六章电子显微术ppt课件.ppt

《第六章电子显微术ppt课件.ppt》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、第六章扫描电子显微书LettuceField(16MDRAM)TheoryofScanningElectronMicroscopeHitachiHigh-TechnologiesCorporationNanoTechnologiesSalesDept.1.ResolutionImprovement30kV1kV0.6nm0.6nm0.5nm2.5nm3.5nm1.8nmS-5200S-5000HS-5000DevelopmentofanewUHRObj.LensNewS-4800FE-SEMResolution:1.0nm15k

2、V1.4nm1kVConfigurationofascanningelectronmicroscopeObjectiveMovableApertureModelS-3000NSpecimenStageCRTElectronGunSEDetectorSpecimenChamberComparisonamongOM,TEMandSEM第一节结构原理扫描电镜基本上是由电子光学系统、信号接收系统、供电系统、真空系统等四部分组成。在扫描电镜中，电子枪发射出来的电子束，经三个电磁透镜聚焦后，成直径20微米~25Å的电子束。置于末级透镜上部的

3、扫描线圈能使电子束在试样表面上做光栅状扫描。试样在电子束作用下，激发出各种信号，信号的强度取决于试样表面的形貌、受激区域的成分和晶体取向。值得强调的是，入射电子束在试样表面上是逐点扫描的，像是逐点记录的，因此试样各点所激发出来的各种信号都可记录下来。给试样的综合分析带来极大的方便。SEDetectorSpecimenCRTCameraAmplifierImageSignalHighVoltageDeflectionCoilsDeflectionAmplifierVacuumPumpFilamentWehneltElectronG

4、unAnodeCondenserLensDeflectionCoilsObjectiveLensSpecimenChamberScanningElectronBeamMag.ControlConfigurationofascanningelectronmicroscopePG1PG2FilamentCondenserLensapertureOrificeNVVacuumGaugeVacuumcontroller(Real-time)VacuumconditionpresetRP1RP2DPLowVacuumConditionBS

5、EdetectorV8V6V9V3V4V1SpecimenV5V7HighVacuumConditionV2BlockdiagramofevacuatingsystemImageSampleObjectiveLens(IlluminationSource)LumpOMCondenserLensProjectionLensScreenImageImageSampleSampleObjectiveLensElectronSourceCondenserLensDeflectionCoilsSEDetectorCRTTEMSEMFluo

6、rescentscreenScanningDifferenceamongOM,TEMandSEMFETipTungstenFilament750μmElectronSourceTypeofEmissionOperatingVacum(Pa)Brightness(A/cm2･str)SourceSize(μm)EnergySpred(eV)LifeTime(h)TungstenFilamentThermonicFieldEmissionColdFE10-5～10-85x105108300.012.00.2502000EnergyS

7、preadEffectofchromaticaberrationΔV=～2eVTungstenFilamentCrossoverofLowEnergyElectronsCrossoverofHighEnergyElectronsΔV=～0.2eVFETipCrossoverofLowEnergyElectronsCrossoverofHighEnergyElectronsWehneltAnodeElectronBeamV0ElectronBeamV01stAnode2ndAnodeFlashingVoltageV1V0:Acce

8、leratingvoltageV1:ExtractionvoltageBiasVoltageControlThermionicEmissionColdFieldEmission(～6.5kV)FilamentCurrentControlFilamentCompa