W.K.CHIMAssociateProfessorDepartmentofElectricalandComputerEngineeringNationalUniversityofSingaporeE-mail:elecwk@nus.edu.sgTel:(65)6516-6287OfficeLocation:E2-03-31EE5514ICYield,Reliability&FailureAnalysisSurfaceAnalysisTechniquesSurfaceAnalysisTechniques•AugerElectronSpectroscopy(AES)•SecondaryIonMassSpectrometry(SIMS)•ElectronSpectroscopyforChemicalAnalysis(ESCA)orX-rayPhotoelectronSpectroscopy(XPS)SurfaceAnalysisTechniques•Background•AugerElectronEmission•AESInstrumentation•AugerSpectrum•DepthProfilingAugerElectronSpectroscopy(AES)AugerElectronSpectroscopy(AES)Background•AESisatruesurfaceanalysistechnique(UnlikeEDS/EDXwhichisabulkanalysistechnique).D.K.Schroder,SemiconductorMaterialandDeviceCharacterization,Wiley,1990,Chapter10.Escapezones•AESisusedtoidentifytheelementalcompositionofsurfacefilms,orwithionsputtering,tomeasuretheconcentrationofelementsasafunctionofdepth(i.e.,depthprofiling).AugerElectronSpectroscopy(AES)Background(Cont’d)•Augerelectronsarelowenergyelectrons(50to2500eV)thatareemittedfromasamplewhenitisscannedbyanelectronbeamofupto5keV.SecondaryElectronsEnergyDistributionAugerElectronsBSEs•HigherenergybeamsproduceAugerelectronsdeeperwithinthesamplethathavelittlechanceofescaping.•ThelowenergyoftheAugerelectronslimittheirescapedepthfromthesampletoonlyafewmonolayersofthesurface.•AESsamplingdepthsistypicallyintheregionofbetween5to50Å.Allelements,withtheexceptionofhydrogenandhelium,canbedetectedusingAES.AugerElectronSpectroscopy(AES)Background(Cont’d)•AESisparticularlysensitivetothelight-elementrange.ItthereforecomplementsX-RaySpectroscopywhichhaslowsensitivityforthelightelements.•AESDetectionLimit:0.1to1%butvariesfromelementtoelement.•QuantitativeAESanalysisisdifficult.Reportedaccuraciesarecurrentlyabout20-50%,with5%precisionforsimplesemiconductorsamples.AugerElectronSpectroscopy(AES)AugerElectronEmission•AprimaryelectronfromtheelectrongunejectsanelectronfromtheKshell.D.K.Schroder,SemiconductorMaterialandDeviceCharacterization,Wile...
