SMT-08 Gas Controls CD.ppt

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1、 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaSemiconductor Semiconductor Manufacturing TechnologyManufacturing TechnologyMichael Quirk&Julian Serda Michael Quirk&Julian Serda October 2001 by Prentice HallOctober 2001 by Prentice HallChapter 8Chapter 8

2、Gas Control Gas Control in Process Chambersin Process Chambers 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaObjectivesAfter studying the material in this chapter,you will be able to:1.Explain why process chambers are used in semiconductor manufacturing.

3、2.Describe the benefits of vacuum,the vacuum ranges and appropriate pumps.3.Explain the need for gas flow in process chambers and how it is controlled.4.Explain what is an RGA and why it is beneficial in process chambers.5.Describe what is a plasma and how it is obtained.6.Discuss the effects of con

4、tamination in chambers and how to minimize it.2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaThe Many Functions of Process ChambersControlling how gas chemicals flow into and react in the chamber in close proximity to the wafer.Creating a vacuum environme

5、nt.Removing undesirable moisture,air and reaction by-products.Creating an environment for chemical reactions such as plasma to occur.Controlling the heating and cooling of the wafer.2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaEarly 1960s Vacuum Bell Ja

6、rBell jarIsolation valveGas moleculesVacuum pumpExhaustFigure 8.1 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaIntegrated Cluster ToolProcess chamberWafer orienterWafer handlerCooldown chamberLoad/unload stationsUsed with permission from Applied Materia

7、ls,Inc.,Endura PECVD systemFigure 8.2 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaVacuumBenefits of VacuumVacuum RangesMean Free Path 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaBenefits of Vacuum in Semi

8、conductor ManufacturingTable 8.1 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaVacuum RangesTable 8.2 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaMean Free Path and Molecular Density Versus PressureTable 8.

9、3 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaVacuum PumpsRoughing PumpDry Mechanical PumpBlower/Booster PumpHigh Vacuum PumpTurbomolecular PumpCryopumpVacuum in Integrated Tools 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Qui

10、rk and Julian SerdaRoughing Pump Exhausting a High Vacuum PumpRoughingpumpHi-vac valveHi-vac pumpProcess chamberFigure 8.3 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaRotary Claw Dry Mechanical PumpExhaust portCompressed gasesRotorsIntake PortStator ho

11、using(a)(b)(c)Used with permission from International SEMATECHFigure 8.4 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaRoots Blower PumpPump outlet to roughing pumpPump inlet connected to process chamberLobes rotate rapidly in opposite directions forcing

12、 gas through the outlet.Figure 8.5 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaTurbo Pump BladesRotorStatorMotorOutletInletStatorStator joinedto pump housingRotorUsed with permission from Varian Vacuum SystemsFigure 8.6 2001 by Prentice HallSemiconduct

13、or Manufacturing Technologyby Michael Quirk and Julian SerdaCryopump Compressor and Pump Module Cryopump housing Cold head Gas linesOutlet to roughing pumpInlet to process chamberCompressorUsed with permission from Varian Vacuum SystemsFigure 8.7 2001 by Prentice HallSemiconductor Manufacturing Tech

14、nologyby Michael Quirk and Julian SerdaCryoarray Surfaces in Pump ModuleFirst-stage cryoarraySecond-stage cryoarrayH2O vaporN2,O2,ArH2,He,NeUsed with permission from Varian Vacuum Systems Figure 8.8 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaCluster T

15、ool Layout with Vacuum EnvironmentWafer orienter Medium vacuumWafer cassette loadlocksAtmosphere to medium vacuumEtch process chambersMedium to high vacuumTurbo pump preceded by a mechanical forepumpWafer transfer chamber Medium vacuum Mechanical roughing pump Figure 8.9 2001 by Prentice HallSemicon

16、ductor Manufacturing Technologyby Michael Quirk and Julian SerdaProcess Chamber Gas FlowThe basic process chamber requirements for gas flow are:*Ability to handle a wide variety of bulk and specialty gases,many of which are corrosive and toxic.The control of gas flow into the process chamber is accu

17、rate and repeatable.The gas mix proportions are able to be controlled during the process run.Materials used in the chamber are not affected by the process gases and do not introduce contaminants into the gas stream._*S.Hansen,Introduction to the Creation and Control of the Vacuum Process Environment

18、,(Andover:MKS Instruments,1995),p.110.2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaThermal Mass Flow ControllerUsed with permission from International SEMATECHFigure 8.10 Heater coilSensor coilMeasuring tubeFlowValveBypassMeasurement and control electro

19、nics 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaMass Flow ControllerPhoto 8.1(Photo courtesy of MKS Instruments,Inc.)2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaBasic Parts of Residual Gas Analyzer(RGA)+

20、V+V-V+-+-+-+-V-V-V+-VElectrons collide with atoms from inside the process chamber to create+ions.Hot filament generates high-energy electrons.The detector recombines electrons with+ions and measures the intensity of specific ion current.High negative voltage accelerates+ion movement.DC and RF voltag

21、es on four rods selectively filter+ions by their respective mass-to-charge value.IonizerApertureQuadrupole AnalyzerDetectorRGA Sensor HeadFigure 8.11 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaQuadrupole Mass FilterSelected+ions of specific mass/charg

22、e to be sampledRejected+ionsFigure 8.12 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaRGA Measurement of a Process ChamberHi-vac pumpProcess chamberRelative Ion Signal Intensity010050Mass Number1444161822 285832NeN2H2OO2NCO2890723B156C4Residual gas analy

23、zerSensorFigure 8.13 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaPlasmaCreation of an IonGlow DischargeRadicalsRF Energy 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaCreation of an Ion F +9An ion is an ato

24、m with an unequal number of protons(+)and electrons(-).Electron separated from host atom.Fluorine atom with one less electron.A positive ion is formed when an atom loses an electron.F +9A neutral particle is an atom with an equal number of protons(+9)and electrons(-9).Fluorine atom has a total of 7

25、valence electrons.Valence ring can hold a maximum of 8 electrons.Valence-shell electron(-)Inner-shell electron(-)Protons(+)in the nucleus(neutrons not shown)Figure 8.14 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaPlasma Glow DischargeVacuum chamberElec

26、trode(1 of 2)Hi-vac pumpPlasmaRF generatorMatching unitFigure 8.15 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaElectrically Exciting and Relaxing an Atom F +9A neutral atom can be electrically excited to raise electrons to a higher energy band.Electron

27、 raised to a higher energy shell.Valence shellInner shellFluorine atom F +9A small packet of light energy called a photon is emitted when a high-energy electron falls back down to the valence shell.Fluorine atomValence shellHigher energy shellPhoton emitted during transition of electron from a highe

28、r state to a lower state.Figure 8.16 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaDissociation of a MoleculeCHF2 radicalHigh-energy electronFluorine(neutral)CHF3 moleculeFluorineFluorineHydrogenCarbonFluorineFluorineFluorineHydrogenCarbonFluorineElectro

29、nCollision results in dissociation of molecule.High-energy electron collides with molecule.Figure 8.17 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaTypical Plasma Electrode ConfigurationPlasmaElectrodeElectrodeDark spaceChamber wallDark spacePlasma pote

30、ntialElectrodeElectrode0 V0 V+_Used with permission from International SEMATECHFigure 8.18 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaProcess Chamber ContaminationTable 8.4 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaChapter 8 ReviewSummary 196Key Terms196Review Questions196Equipment Suppliers Web Sites197References197