Introduction to Sentaurus TCAD

IntroductiontoSentaurusTCADDavidPennicard–[e-mail]ntaurusTCAD,visit:[um]Y[um]-40-2002001020304050DopingConcentration[cm^-3]9.7E+172.9E+158.9E+12-9.2E+12-3.0E+15-1.0E+1801:Tutorial/StripDetector/n5_msh.grd:n5_msh.datOverview•IntroductiontoSentaurusTCADsoftware•Buildingthedevicestructure•Runningthesimulation•Viewingresults•OthersoftwareExamplesimulations–3Ddetectors•3Ddetector–photodiodedetectorwithelectrodecolumnspassingthroughsubstrate–Smallelectrodespacinggivesfastcollection,lowVdep–Radiationhardness+ve+veholes-veelectronsLightlydopedp-typesiliconn-typeelectrodep-typeelectrodeParticle+ve+veholes-veelectronsLightlydopedp-typesiliconn-typeelectrodep-typeelectrodeParticleAround30µm+ve+ve-veholes300µmn-typeelectrodep-typeelectrodeelectronsParticleAround30µm+ve+ve-veholes300µmn-typeelectrodep-typeelectrodeelectronsParticlePlanar3D2500500030000400004000065000100002000020000D(um)Z(um)01020304001020304050601300009000060000400003000020000100000Detailofelectricfield(V/cm)aroundtopofdouble-sided3Ddevice(100Vbias)130000n+p+Electricfield(V/cm)Examplesimulations–3DdetectorsOxidelayern+column250umlength10umdiameterp-stopInnerradius10umOuterradius15umDose1013cm-255umpitchp-substrate300umthick,doping7*1011cm-3Seperatecontacttoeachn+columnOnbackside:OxidelayercoveredwithmetalAllp+columnsconnectedtogetherStructureofdouble-sided3Ddevicep+column250umlength10umdiameterElectricfieldpatterninanewdevicestructureExamplesimulations–3DdetectorsCapacitance-voltagecharacteristicsCurrentpulseproducedovertimeasparticlehitsdetectorExampleprojects–3Ddetectors051015202505101520250246810121410126911p+n+Y(m)Chargecollection(ke-)X(m)02.04.06.08.0101214Multipleparticletracksimsmapchargecollectionwithhitposition(afterradiationdamage)020406080050100150200250Fit:V=0.07(X-13.5m)2-1.5765438Bias(V)Electrodespacing(m)DepletionvoltageMultipledepletionsimulationsfindVdepforpossibleATLAS3Dstructures(afterradiationdamage)Basicsofsimulation•Thestructureofadeviceisapproximatedbya“mesh”consistingofalargenumberofdiscreteelements–Thiscanbe1D,2Dor3D–Choicedependsonsymmetryofdevice•Differentialequationsdescribingtheelectricpotentialandcarrierdistributionsareappliedtoeachelement–Endupwithverylargenumberofequations!•Chooseboundaryconditionsforthesimulation–E.g.potentialsateachelectrode•Solvetheequationstofindthepotentialandcarrierconcentrationsineachelement–Softwareusesanumericalsolver–iteratesrepeatedlyuntilsolutionisaccurateenoughSimulationpackagesCreatemeshRunsimulationViewresultsProcesssimulationSentaurusProcess(optional){dios}LigamentcangeneratecommandfilesforProcessMesh,noffset3dcreatedevicemeshesusingacommandfileSentaurusStructureEditor(andMDraw)createmesheswithGUISentaurusDevice{dessis}Inspect–Plottinggraphsofelectrodecurrentsetc.Tecplot–Producingimagesofelectricfieldpatternsetc.throughoutdeviceWorkbench–CanrunlargenumbersofsimulationsconvenientlyProjectcontrolExampleofsimulationflowMesh*msh.bnd-boundaryfile*msh.cmd-commandfileInspectSentaurusDevice*msh.grd–gridfile(structureofmesh)*msh.dat–dopingfile(dopingateachpoint)*des.cmd–commandfile*des.plt–currentfileTecplot*des.dat–plotfilesImagefiles(E-fieldetc.)Graphs(imagesorexporteddata)StripdetectorsimulationFilesavailableinSENTAURUS/Seminar/IntroductionOverview•IntroductiontoSentaurusTCADsoftware•Buildingthedevicestructure•Runningthesimulation•Viewingresults•OthersoftwareMesh•Meshtakesa“boundary”(.bnd)andcommand(.cmd)filesasarguments:–meshStripDetectorX[um]Y[um]-40-2002001020304050DopingConcentration[cm^-3]9.7E+172.9E+158.9E+12-9.2E+12-3.0E+15-1.0E+1801:Tutorial/StripDetector/n5_msh.grd:n5_msh.datReadoutcontactOxidelayerN+implantP-sprayNotevariationinmeshspacingMeshinputfiles•StripDetector.bndboundaryfiledescribesmaterials&contacts•StripDetector.cmddescribesdopingprofilesandmeshrefinement–Thesearedefinedfirst,thenplaced–Doping:Siliconsubstrate{rectangle[(-50,0)(50,300)]}OxideTopOxide1{rectangle[(-40,-0.5)(-10,0)]rectangle[(10,-0.5)(40,0)]}Contactnplus2{line[(-10,0)(10,0)]}…….Definitions{AnalyticalProfilen-pluselectrode{Species=PhosphorusActiveConcentrationFunction=Gauss(PeakPos=0,PeakVal=1e18,ValueAtDepth=1e+12,Depth=1)Lateralfunction=Gauss(Factor=0.8)}……}Meshinputfiles•Meshrefinements:–Smallelements=moreaccuratebutslowersimulation–So,userefinementstatementstogetsmallestspacinginregionswithdopingprofiles,highelectricfields,chargegenerationetc.–3Dsimulationshavemoreelements,andrunfarslower,sogoodmeshdesigniscrucial!Definitions{Refinementn-electrode{MaxElementSize=(2.52)MinElementSize=(0.10.1)Refinefunction=MaxTransDifference(Variable=DopingConcentration,Value=2)}……}Placements{Refinementn-electrodesinstance{Reference=n-electrodeRefineWindow=rectangle[(-500),(503)]}.......}Meshdesignconsiderations•Boundaryconditions–DefaultboundaryconditionsarethatEandcarriercurrentsperpendiculartoboundaryarezero–So,boundariesshouldeitherbefarenoughfromactiveregionnottoha