Radiationdamagemodels:comparisonbetweenSilvaco andSynopsys
J.Beyera),M.Bomben b),A.Macchioloa),R.Nisiusa)a)MaxPlanckInstitutfürPhysik,Münchenb)LPNHE&Université ParisDiderot,Paris
20-22.11.201731st RD50Workshop
Introduction&Outline
TCADsimulationbecameanessentialtoolwhendesigningsiliconpixelsensorsandpredictingtheirproperties.
Twomaintoolsareavailable:Silvaco andSynopsysTCADtools.
Aretheycompatiblewithoneanotherindefaultsettingsandsimplequestions?
Docommonradiationdamagemodelsdevelopedwithoneofthem,alsoworkfortheother?
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 2
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 3
SetupforthecomparisonStructureandperspectives
• useasimple2DTCADmodeltoreduceanypossibledifferencearisingfromdifferentimplementationsofthestructure
• aims:• compareCVandIVcurvesfornot-irradiated
caseatvarioustemperatures
• compareCV,IVandCCE(MIPbased)afterirradiation• comparethemodelswithonesimulator• comparethesimulatorswithonemodel
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 4
SetupforthecomparisonRadiationdamagemodels
• radiationdamageinTCAD:• bulkdamage:
• trapscharacterisedbyenergylevel,e/hcross-sectionandintroductionrate
• useNewDelhi1 andPerugia20172 irradiationmodelhere
• surfacedamage:• fixedoxidechargeof1×1011cm-2 fornot-irradiatedand
1×1012cm-2 forirradiatedsensors• nointerfacetraps
• radiationlevel:1×1015 neqcm-2
• temperature:-20oC,0oC,20oC
1 R.Dalal etal.,SimulationofIrradiatedSiDetectors,PoS Vertex2014(2015).
2 F.Moscatelli etal.,EffectsofInterfaceDonorTrapStatesonIsolationPropertiesofDetectorsOperatingatHigh-LuminosityLHC,IEEETrans.onNucl.Science2017
Perugia2017
New
Delhi
EnergylevelsbasedonworkofEremin /Verbitskaya /Li
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 5
SetupforthecomparisonStructureofinterest
highresistivityp-typebulkmaterial(3×1012cm-3)
n+ pixelimplant
aluminumcontacttoimplant
SiO2
passivation:
electricalcontactontopofthealuminum
simulatedthicknesses:200µm
6
SetupforthecomparisonPhysicsmodels- Synopsys
Mobility:• dopingdependentmobilityaccordingtoMasetti model:
• highfieldsaturationaccordingtoextendedCanali model(Electricalfieldasdrivingforce):
Recombination:• Shokley-Read-Hall(with
doping,temperatureandelectricfield(Hurx lifetime)dependence)
• noavalanche
Band-gapnarrowing• OldSlotboom
FormulasfromSynopsyssDevicemanual
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 7
SetupforthecomparisonPhysicsmodels- Silvaco
Mobility:• Lookuptabledependingonconcentrationandsimplepowerlawtemperaturedependence.• Fielddependentmobilitymodel:Caughey andThomasforlowfieldregime;Schwarz andRusse forhighfield
Recombination:• ConcentrationdependentSRHrecombinationterm(Roulston,Arora andChamberlain- Law– Fossum,Leeand
Lee)
Band-gapnarrowing• Klaassen model
Wanttocross-checkphysicsmodelsonebyoneacrossthetwosimulatorsinthefuture!
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 8
FirsttestsNot-irradiatedstructure– CVcurves
• comparingCVcurvesatvarioustemperatures• notemperaturedependencebetween
-20oCand20oC
• Synopsysvs.Silvaco• risingetdge matchesperfectly• stepinplateauobservedwithSilvaco
butnotwithSynopsys• butagreementintheimportant
(pre)-depletionregionisat%level
0 100 200 300 400 500 [V]bias V
0
200
400
600
800
1000
1200
1400
1600
3010´]-2
[F-2 C
= 0, Synopsys vs. SilvacoFC2V,
Silvaco - T = 20 CSynopsys - T = 20 CSilvaco - T = 0 CSynopsys - T = 0 CSilvaco - T = -20 CSynopsys - T = -20 C
10kHz
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 9
FirsttestsNot-irradiatedstructure– IVcurves
• comparingIVcurvesatdifferenttemperatures
• Synopsysvs.Silvaco• Synopsyspredictsslightlyincreasing
plateaucurrent• differencesbetweenSilvaco and
Synopsysincreasewithincreasingtemperature
• bigdifferenceinpredictedplateau• whatisthecause?
0 100 200 300 400 500 [V]bias V
16-10
15-10
14-10
13-10
12-10
[A]
leak
I
= 0, Synopsys vs. SilvacoFIV,
Silvaco - T = 20 CSynopsys - T = 20 CSilvaco - T = 0 CSynopsys - T = 0 CSilvaco - T = -20 CSynopsys - T = -20 C
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 10
FirsttestsNot-irradiatedstructure– IVcurves,closerlook
• comparingIVcurvesat20oC,varythecarrierlifetimeτ
• canjointhetwosimulatorsbyartificiallychangingthecarrierlifetime
• thedifferencesindefaultτ betweenSilvacoandSynopsysshouldn’tmatterafterirradiation
0 100 200 300 400 500 [V]bias V
0
0.2
0.4
0.6
0.8
1
1.2
12-10´
[A]
leak
I
Silvaco = 1.0e-5 stSilvaco - = 0.933e-5 stSilvaco - = 1.388e-5 stSilvaco -
tSynopsys - std = 1.0e-5 s tSynopsys - = 1.0e-5 s - no conc. dep.tSynopsys -
IrradiatedStructure– 1×1015neqcm-2
1.comparingPerugiaandNewDelhimodels(Synopsys)
2.comparingSynopsysandSilvaco (Perugiamodel)
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 11
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 12
Comparisonofmodels- SynopsysIrradiatedstructure– CVcurves
• comparingCVcurvesatvarioustemperatures
• depletionwithPerugia2017inareasonablerangeof100-200V
• smalltemperaturedependence
• depletionwithNewDelhiat650->>2000Vbiasvoltage
• hugetemperaturedependence• expectedgiventheenergylevels
aremuchclosertotheintrinsiclevelthaninPerugiamodel
0 500 1000 1500 2000 [V]bias V
0
200
400
600
800
1000
1200
1400
1600
3010´]-2
[F-2
C
, New Delhi vs. Perugia 20172/cmeq = 1e15 nFC2V,
Perugia, T = 20 CNew Delhi, T = 20 CPerugia, T = 0 CNew Delhi, T = 0 CPerugia, T = -10 CNew Delhi, T = -10 CPerugia, T = -20 CNew Delhi, T = -20 C
10kHz
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 13
Comparisonofmodels- SynopsysIrradiatedstructure– IVcurves
• comparingIVcurvesatvarioustemperatures
• significantlyhighercurrentwithNewDelhimodel
• NewDelhipredictsincreasingplateaucurrent,shouldbeduetonodepletionyet
• differencesbetweenthemodelsgetsmallerforincreasingtemperature
0 200 400 600 800 1000 1200 1400 [V]bias V
13-10
12-10
11-10
10-10
9-10
[A]
leak
I
/cm^2, New Delhi vs. Perugia 2017eq = 1e15 nFIV,
New Delhi, T = 20 CPerugia T = 20 CNew Delhi, T = 0 CPerugia T = 0 CNew Delhi, T = -20 CPerugia T = -20 C
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 14
Comparisonofmodels- SynopsysIrradiatedstructure– chargecollectionefficiency
• comparingCCEatdifferenttemperatures• temperaturedependenceforPerugia
modelmainlyintherisingedgeinagreementwithdepletionvoltagevariation
• NewDelhimodelseemstoexhibitmoredifferenceforhigherbiasvoltages
• comparingNewDelhiandPerugia2017model• significantlylesschargecollectedusing
NewDelhimodel• plateauisnotyetreachedat1000V• reason:bulknotyetdepleted(C-2V) 100 200 300 400 500 600 700 800 900 1000
[V]bias V0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
CC
E [%
]
, New Delhi vs. Perugia 20172/cmeq = 1e15 nFCCE,
New Delhi, T = 20 CPerugia T = 20 CNew Delhi, T = -20 CPerugia T = -20 C
IrradiatedStructure– 1×1015neqcm-2
1.comparingPerugiaandNewDelhimodels(Synopsys)
2.comparingSynopsysandSilvaco (Perugiamodel)
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 15
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 16
ComparisonofSimulators- PerugiaIrradiatedstructure– CVcurves
• compareCVcurvesfrombothsimulatorsatdifferenttemperatures• overallgoodagreementbetween
SynopsysandSilvaco• differencesincreasingwithincreasing
temperature• differenceisbetween10V– 30V
0 100 200 300 400 500 [V]bias V
0
200
400
600
800
1000
1200
1400
1600
3010´]-2
[F-2 C
, Synopsys vs. Silvaco, Perugia 20172/cmeq = 1e15 nFC2V,
Synopsys - T = 20 CSilvaco - T = 20 CSynopsys - T = 0 CSilvaco - T = 0 CSynopsys - T = -20 CSilvaco - T = -20 C
10kHz
17
ComparisonofSimulators- PerugiaIrradiatedstructure– closerlook:CVcurves
Tool Silvaco Synopsys
Vdepl [V] ~240 ~160
0 100 200 300 400 500 [V]bias V
0
200
400
600
800
1000
1200
1400
1600
3010´]-2
[F-2 C
= 1e15, T = 20C, Perugia 2017FC2V,
Silvaco
=1e-5s, no avalanche, reduced physicstSynopsys,
• investigatingtheimpactofphysicsmodels
• startwithSynopsysreducedphysicsandadaptedcarrierlifetimetomatchIVnot-irr
10kHz
0 100 200 300 400 500 [V]bias V
0
200
400
600
800
1000
1200
1400
1600
3010´]-2
[F-2 C
= 1e15, T = 20C, Perugia 2017FC2V,
Silvaco
=1e-5s, no avalanche, reduced physicstSynopsys,
=1e-5s, no avalanchetSynopsys, Perugia physics,
18
ComparisonofSimulators- PerugiaIrradiatedstructure– closerlook:CVcurves
Tool Silvaco Synopsys +physics
Vdepl [V] ~240 ~160 ~400V
• investigatingtheimpactofphysicsmodels
• startwithSynopsysreducedphysicsandadaptedcarrierlifetimetomatchIVnot-irr
• useadvancedphysicsmodelsasusedbythePerugiagroup 10kHz
19
ComparisonofSimulators- PerugiaIrradiatedstructure– closerlook:CVcurves
Tool Silvaco Synopsys +physics +default 𝛕
Vdepl [V] ~240 ~160 ~400V ~220
0 100 200 300 400 500 [V]bias V
0
200
400
600
800
1000
1200
1400
1600
3010´]-2
[F-2 C
= 1e15, T = 20C, Perugia 2017FC2V,
Silvaco
=1e-5s, no avalanche, reduced physicstSynopsys,
=1e-5s, no avalanchetSynopsys, Perugia physics,
, no avalanchetSynopsys, Perugia physics, default
• investigatingtheimpactofphysicsmodels
• startwithSynopsysreducedphysicsandadaptedcarrierlifetimetomatchIVnot-irr
• useadvancedphysicsmodelsasusedbythePerugiagroup
• usethedefaultcarrierlifetimeagain10kHz
20
ComparisonofSimulators- PerugiaIrradiatedstructure– closerlook:CVcurves
Tool Silvaco Synopsys +physics +default 𝛕
Vdepl [V] ~240 ~160 ~400V ~220
0 100 200 300 400 500 [V]bias V
0
200
400
600
800
1000
1200
1400
1600
3010´]-2
[F-2 C
= 1e15, T = 20C, Perugia 2017FC2V,
Silvaco
=1e-5s, no avalanche, reduced physicstSynopsys,
=1e-5s, no avalanchetSynopsys, Perugia physics,
, no avalanchetSynopsys, Perugia physics, default
, avalanche ontSynopsys, Perugia physics, default
• investigatingtheimpactofphysicsmodels
• startwithSynopsysreducedphysicsandadaptedcarrierlifetimetomatchIVnot-irr
• useadvancedphysicsmodelsasusedbythePerugiagroup
• usethedefaultcarrierlifetimeagain• addavalanche
10kHz
21
ComparisonofSimulators- PerugiaIrradiatedstructure– closerlook:CVcurves
Tool Silvaco Synopsys +physics +default 𝛕
Vdepl [V] ~240 ~160 ~400V ~220
• investigatingtheimpactofphysicsmodels
• startwithSynopsysreducedphysicsandadaptedcarrierlifetimetomatchIVnot-irr
• useadvancedphysicsmodelsasusedbythePerugiagroup
• usethedefaultcarrierlifetimeagain• addavalanche• comparetodatasimulatedbythePerugia
group
0 100 200 300 400 500 [V]bias V
0
200
400
600
800
1000
1200
1400
1600
3010´]-2
[F-2 C
= 1e15, T = 20C, Perugia 2017FC2V,
Silvaco
=1e-5s, no avalanche, reduced physicstSynopsys,
=1e-5s, no avalanchetSynopsys, Perugia physics,
, no avalanchetSynopsys, Perugia physics, default
, avalanche ontSynopsys, Perugia physics, default
Synopsys, Perugia group data
Cfr.Bomben,28th RD50WS,Torino,June2016
10kHz
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 22
ComparisonofSimulators- PerugiaIrradiatedstructure– influenceoffrequencyonCV
0 100 200 300 400 500 [V]bias V
0
200
400
600
800
1000
1200
1400
1600
1800
3010´]-2
[F-2 C
, Perugia 20172/cmeq n1510´ = 1F = 0.45 kHz, t = -10 C, nC2V,
= 10 kHz - Synopsysn = 10 kHz - Silvacon = 0.45 kHz - Synopsysn = 0.45 kHz - Silvacon
• compareC-2Vwiththedefault10kHzand0.45kHzat-10oCforbothsimulators
• sametrendofhigherdepletionvoltageforhigherfrequency
• smallerinfluenceonSilvaco simulation• overallsmallinfluenceonly
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 23
ComparisonofSimulators– DelhiIrradiatedstructure– influenceoffrequencyonCV
0 500 1000 1500 2000 2500 3000 [V]bias V
0
200
400
600
800
1000
1200
1400
1600
1800
3010´]-2
[F-2 C
, New Delhi2/cmeq n1510´ = 1F = 0.45 kHz, t = -10 C, nC2V,
= 10 kHz - Synopsysn = 10 kHz - Silvacon = 0.45 kHz - Synopsysn = 0.45 kHz - Silvacon
• compareC-2Vwiththedefault10kHzand0.45kHzat-10oCforbothsimulators
• sametrendofhigherdepletionvoltageforlowerfrequency(oppositeofPerugia)
• smallerinfluenceonSilvaco simulation• hugeinfluencebyfrequency
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 24
ComparisonofSimulators- PerugiaIrradiatedstructure– IVcurves
• compareIVcurvesfrombothsimulatorsatdifferenttemperatures• smalldifferencebetweenthetwo• currentlowerinSynopsys• constantratio– differencecouldbedue
totemperaturescaling
Evaluationofthecurrentrelateddamagerateαat20C(norescalefortemperatureneeded)gives:
Tool Silvaco Synopsys
α[10-17 A/cm] 4.2±0.1 3.5±0.10 200 400 600 800 1000
[V]bias V
13-10
12-10
11-10
10-10
9-10
[A]
leak
I
, Synopsys vs Silvaco, Perugia 20172/cmeq = 1e15 nFIV,
Silvaco - T = 20 CSynopsys - T = 20 CSilvaco - T = 0 CSynopsys - T = 0 CSilvaco - T = -20 CSynopsys - T = -20 C
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 25
ComparisonofSimulators- PerugiaIrradiatedstructure– chargecollectionefficiency
• comparechargecollectionefficiencyforPerugiamodelat-20oCand20oC
• normalised tocollectedchargeat200V-500V,beforeirradiation
• exactsamerisingedge• sametemperaturedependence• plateauefficiencydifferentby~5%
100 200 300 400 500 600 700 800 900 1000 [V]bias V
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
CC
E [%
]
, Synopsys vs. Silvaco, Perugia 20172/cmeq = 1e15 nFCCE,
Silvaco - T = 20 CSynopsys - T = 20 CSilvaco - T = -20 CSynopsys - T = -20 C
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 26
ComparisonofSimulators- DelhiIrradiatedstructure– chargecollectionefficiency
100 200 300 400 500 600 700 800 900 1000 [V]bias V
0
0.1
0.2
0.3
0.4
0.5
0.6
CC
E [%
]
, Synopsys vs. Silvaco, New Delhi2/cmeq = 1e15 nFCCE,
Silvaco - T = 20 CSynopsys - T = 20 CSilvaco - T = -20 CSynopsys - T = -20 C
• comparechargecollectionefficiencyforNewDelhimodelat-20oCand20oC
• bothdonotreachaplateau• efficiencydifferentby~14%at1000V
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 27
Summary
1. ComparingNewDelhiandPerugia2017radiationdamagemodels• depletionvoltagemuchhigherandmuchlargertemperaturedependenceusingNewDelhimodel• highercurrentsandnosaturationofcurrentupto1500Vgiventhehighdepletionvoltage• CCEis~80%forPerugiaand~50%forNewDelhi@1000Vand1x15neq/cm2
2. ComparingSynopsysandSilvaco TCADtools• CVagreesdowntothe%levelbeforeirradiation,afterirradiationsmalldifferenceswithPerugiamodel• IVdifferentbeforeirradiationduetodifferentτ value,afterirradiationclosetogether,compatiblewith2016data• CCEingoodagreementintherisingedge,plateauslightlydifferent,differenceis5%-14%
3. Outlook:• projecthasjuststarted,morecooperationplanned
• DEFPIXELSproject,EmbassyofFranceinGermanyandDAADProcope grantcall• comparethephysicsmodelsinmoredetailbetweenthetwosimulators• morecomplexstructurestospothigherorderdifferences• compareavalanchemodels
Thankyouforyourattention!
Backup
21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 28