Technology Computer Aided Design for Si, SiGe and GaAs Integrated Circuits

457 Pages·2007·3.97 MB·English

by  C.K. Maiti

IETCIRCUITS,DEVICESANDSYSTEMSSERIES21
TCAD for Si,
SiGe and GaAs
Integrated Circuits
Othervolumesinthisseries:
Volume2 AnalogueICdesign:thecurrent-modeapproachC.Toumazou,F.J.Lidgey
andD.G.Haigh(Editors)
Volume3 Analogue–digitalASICs:circuittechniques,designtoolsandapplications
R.S.Soin,F.MalobertiandJ.France(Editors)
Volume4 Algorithmicandknowledge-basedCADforVLSIG.E.TaylorandG.Russell
(Editors)
Volume5 Switchedcurrents:ananaloguetechniquefordigitaltechnology
C.Toumazou,J.B.C.HughesandN.C.Battersby(Editors)
Volume6 High-frequencycircuitengineeringF.Nibleretal.
Volume8 Low-powerhigh-frequencymicroelectronics:aunifiedapproach
G.Machado(Editor)
Volume9 VLSItesting:digitalandmixedanalogue/digitaltechniquesS.L.Hurst
Volume10 DistributedfeedbacksemiconductorlasersJ.E.Carroll,J.E.A.Whiteawayand
R.G.S.Plumb
Volume11 Selectedtopicsinadvancedsolidstateandfibreopticsensors
S.M.Vaezi-Nejad(Editor)
Volume12 Strainedsiliconheterostructures:materialsanddevicesC.K.Maitim,
N.B.ChakrabartiandS.K.Ray
Volume13 RFICandMMICdesignandtechnologyI.D.Robertsonand
S.Lucyzyn(Editors)
Volume14 DesignofhighfrequencyintegratedanaloguefiltersY.Sun(Editor)
Volume15 Foundationsofdigitalsignalprocessing:theory,algorithmsand
hardwaredesignP.Gaydecki
Volume16 WirelesscommunicationscircuitsandsystemsY.Sun(Editor)
Volume17 Theswitchingfunction:analysisofpowerelectroniccircuitsC.Marouchos
Volume18 Systemonchip:nextgenerationelectronicsB.Al-Hashimi(Editor)
Volume20 LowpowerandlowvoltagecircuitdesignwiththeFGMOStransistor
E.Rodriguez-Villegas
TCAD for Si,
SiGe and GaAs
Integrated Circuits
G.A. Armstrong
Queen’s University Belfast, Northern Ireland
C.K. Maiti
Indian Institute of Technology, Kharagpur
TheInstitutionofEngineeringandTechnology
PublishedbyTheInstitutionofEngineeringandTechnology,London,UnitedKingdom
©2007TheInstitutionofEngineeringandTechnology
Firstpublished2007
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BritishLibraryCataloguinginPublicationData
Maiti,C.K.
TCADforSi,SiGeandGaAsintegratedcircuits.-(Circuits,devices&systems;v.21)
1.Integratedcircuits-Designandconstruction
2.Computer-aideddesign
I.TitleII.Armstrong,G.A.III.InstitutionofEngineeringandTechnology
621.3’815
ISBN978-0-86341-743-6
TypesetinIndiabyNewgenImagingSystems(P)Ltd,Chennai
PrintedintheUKbyAthenaeumPressLtd,Gateshead,Tyne&Wear
Contents
Preface ix
1 Introduction 1
1.1 Historyofdevicesimulation 8
1.2 Historyofprocesssimulation 10
1.3 EvolutionofTCAD 12
1.4 Processflowintegration 13
1.5 TCADandcompactmodel 15
1.6 Parameterextraction 17
1.7 Statisticalprocesscontrolandyieldanalysis 18
1.8 Virtualwaferfabrication 19
1.9 Optimisation 20
1.10 TCADfornanoelectronics 20
1.11 Interconnect 23
1.12 Summary 23
References 25
2 ICtechnologyandTCADtools 31
2.1 Processsimulation 32
2.1.1 Oxidation 33
2.1.2 Ionimplantation 33
2.1.3 Diffusion 34
2.1.4 Lithography 35
2.1.5 Etching 37
2.1.6 Metallisation 37
2.2 Plasmaprocessing 40
2.3 Chemicalmechanicalpolishing 43
2.4 SynopsysTCADTools 44
2.5 SILVACO:TCADsimulationsuite 46
2.5.1 ATHENA 47
2.5.2 ATLAS 47
vi TCADforSi,SiGeandGaAsintegratedcircuits
2.6 Process-to-devicesimulationusingSILVACO 48
2.6.1 Devicegeneration 49
2.6.2 Devicesimulation 50
2.7 Simulationexample:strained-SiMOSFET 54
2.8 Summary 56
References 58
3 DiffusionandoxidationofSiGe/SiGeCfilms 63
3.1 Boronout-diffusion 63
3.2 Diffusion:Binstrained-SiGe 65
3.3 Diffusion:PandAsinstrained-SiGe 70
3.4 DopantdiffusioninSiGeC 75
3.5 Oxidation:SiGe/SiGeCfilms 79
3.5.1 Oxidationkinetics 80
3.5.2 PlasmaoxidationofSiGefilms 84
3.6 Summary 88
References 89
4 Strain-engineeredMOSFETs 97
4.1 Scalingissues 100
4.2 Mobility-enhancedsubstrateengineering 102
4.2.1 Orientation-dependentmobilityengineering 104
4.2.2 Mobilityenhancementbyprocess-inducedstress 106
4.2.3 Mobilityenhancementbysubstrate-inducedstrain 111
4.3 Channelengineering 117
4.4 Gateengineering 120
4.5 Strained-engineeredCMOStechnology 127
4.6 Layoutengineering 132
4.7 Strain-engineeredMOSFETs:simulation 136
4.8 Summary 143
References 143
5 SOIMOSFETs 153
5.1 FabricationofSOIwafers 154
5.2 SOIdevices 158
5.2.1 PartiallydepletedSOItransistors 160
5.2.2 FullydepletedSOItransistors 162
5.3 Double-gateMOSFET 163
5.4 TCADsimulationofSOIdevices 165
5.5 SimulationusingMASTAR 168
5.6 Strained-SiMOSFETsonSOI 171
5.6.1 SimulationofSSGOIMOSFETs 173
5.6.2 MCsimulationofsSOIMOSFETs 180
5.7 Modellingofmulti-gateSOIdevices 184
5.8 Summary 188
References 189
Listofcontents vii
6 Heterostructurebipolartransistors 195
6.1 ThefirstSiGetransistor 199
6.2 Issuesrelatedtoheterostructure 200
6.3 SiGematerials 204
6.3.1 UHVCVDgrowthofSiGefilms 206
6.4 PhysicsofSiGeHBTs 208
6.5 FiguresofmeritofSiGeHBTs 211
6.6 SimulationofSiGeHBTs 213
6.7 TransittimeinSiGeHBTs 219
6.8 SiGeHBTsatlowtemperature 220
6.9 Summary 224
References 227
7 SiGe/SiGeCHBTtechnology 233
7.1 SiGe-BiCMOStechnology 238
7.2 IBMSiGe-BiCMOStechnology 240
7.2.1 Base-during-gateprocess 240
7.2.2 Base-after-gateprocess 243
7.3 SiGeHBTsonSOI 245
7.4 ComplementarySiGeHBTtechnology 247
7.5 SiGeCHBTtechnology 249
7.6 TCAD:SiGe/SiGeCBiCMOSprocess 254
7.7 Summary 259
References 260
8 MOSFET:compactmodels 267
8.1 Charge-basedMOSFETmodels 268
8.2 Surface-potentialbasedMOSFETmodels 271
8.2.1 SPmodel 273
8.2.2 HiSIM 275
8.2.3 MOSmodel11 275
8.2.4 EKVmodel 277
8.3 Modelevaluation 279
8.4 ModellingofSOIMOSFETs 280
8.5 ModellingofheterostructureMOSFETs 281
8.6 RFMOSmodelling 285
8.7 Large-signalMOSFETmodels 287
8.8 Summary 295
References 295
9 HBT:compactmodels 301
9.1 Advancedmodels 304
9.2 VBICmodel 305
9.3 MEXTRAMmodel 310
9.4 TheHICUMmodel 312
9.5 Parameterextraction 314
viii TCADforSi,SiGeandGaAsintegratedcircuits
9.6 Extractionalgorithm 316
9.7 VBICmodelimplementationinSPICE 323
9.8 TRADICA 332
9.9 Scalablemodelling:SiGe/SiGeCHBTs 333
9.10 RoleofTCAD 339
9.11 Summary 341
References 343
10 Designandsimulationofhigh-speeddevices 351
10.1 SiGevs.GaAsHBTs 354
10.2 Devicesimulation 356
10.2.1 Devicesimulators 357
10.3 Materialparameters 359
10.3.1 Bandgapandbandgapnarrowing 361
10.3.2 Conductionbanddensityofstates 365
10.3.3 Valencebanddensityofstates 366
10.3.4 Si Ge mobility 368
1−x x
10.3.5 Saturationvelocity 372
10.3.6 Generationandrecombination 373
10.3.7 Impactionisation 375
10.4 SimulationofIII–Vdevices 376
10.5 ComparisonofHBTs 384
10.6 RFMOSvs.HBTs 390
10.7 Summary 394
References 397
11 Passivecomponents 409
11.1 Inductor 411
11.1.1 Inductormodeldescription 414
11.1.2 Qualityfactor 417
11.2 Parameterextraction 418
11.3 Inductorsimulation 421
11.3.1 ASITIC 423
11.4 Activeinductors 425
11.5 Capacitors 427
11.6 Varactor 429
11.7 Resistor 430
11.8 Interconnects 431
11.9 Summary 434
References 434
Index 439
Preface
The 2005 International Technology Roadmap for Semiconductors (ITRS) predicts
thattheuseofTechnologycomputer-aideddesign(TCAD)willprovideasmuchas
a40percentreductionintechnologydevelopmentcostsbyreducingthenumberof
experimentallotsandshorteningdevelopmenttimeforthesemiconductorindustry.In
ahighlycompetitivemanufacturingenvironment,oneneedstotakethefulladvantage
ofthepredictivepowerofTCADtoreducecostandtimeforproductdevelopment.
Currently, process and device simulation has established itself as an indispensable
toolfordevelopingandoptimisingdeviceandmicroelectronicprocesstechnologies
intheR&Dphase. Withthedevicecompactmodelparameterextractionforcircuit
analysis, TCAD can be extended into manufacturing for advanced process control
andparametricyieldanalysis.
Inadditiontotherisingcostsofsemiconductorprocessandproductdevelopment,
eachtechnologygenerationisdrivingtowardshigherperformanceandincreasedcom-
plexity. Thechallengeofanalysingadvancedsemiconductorprocessesanddevices
through numerical simulations have been our main motivation for this monograph.
ThepurposeistobringvariousaspectsofTCADformicroelectronicapplicationsinto
oneresource,presentingacomprehensiveperspectiveofthefield.Theaimisalsoto
providedeviceandprocessengineerswithexamplesoftheTCADsimulationapplied
toanumberofdifferenttechnologies,illustratingaquantitativelinkbetweenthebasic
technologicalparametersandelectricalbehaviourofmicroelectronicdevices.
In Chapter 1, the key developments in TCAD from the early research to the
presentday,leadingtoabriefsummaryofthecurrentstatusandroleofTCADtools
fornanoelectronicdevices,arepresented.Chapter2describeskeytechnologyissues
formicroelectronicfabricationandintroducesthereadertocommercialTCADsim-
ulation tools. This chapter also considers how process simulation can be linked to
devicesimulationtodeterminekeyindicatorsofdeviceperformance,illustratedby
simulationresultsofseveraldevicestructuresbasedonAlGaAs/InGaAs/GaAsand
strained-Siheterostructures.Chapter3describesissuesrelatingtooxidationanddif-
fusionmodellingforSiheterostructures(SiGeandSiGeC)andtheirimplementation
inSilvacotoolATHENA.
Chapter 4 deals with the topical field of strain-engineered MOSFETs. Various
strategiesforenhancementofelectronandholemobility,includingprocess-induced