SMT-02_Materials_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 2Chapter 2

2、Characteristics of Characteristics of Semiconductor MaterialsSemiconductor Materials 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaObjectivesAfter studying the material in this chapter,you will be able to:1.Describe the atom,including valence shell,band

3、theory and ions.2.Interpret the periodic table with regards to main group elements and explain how ionic and covalent bonds are formed.3.State the three classes of materials and describe each one with regards to current flow.4.Explain resistivity,resistance,capacitance and discuss their importance t

4、o wafer fabrication.5.Describe pure silicon and give four reasons why it is the most common semiconductor material.6.Explain doping and how the trivalent and pentavalent dopant elements make silicon a useful semiconductor material.7.Explain p-type(acceptor)silicon and n-type(donor)silicon,how silico

5、n resistivity changes with the addition of a dopant,and the PN junction.8.Discuss alternative semiconductor materials,with emphasis on gallium arsenide.2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaAtomic StructureMatterElementNucleusProtonNeutronOrbital

6、 ShellElectronMoleculeCompoundElectronsElectron EnergyValence ShellsEnergy-Band TheoryIons 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaElementary Model of the Carbon AtomCarbon atom:The nucleus contains an equal number of protons(+)and neutrons(6 each)

7、.Six electrons(-)orbit around the nucleus.Valence electronElectron(negative charge)Neutron(neutral charge)Atomic number(number of protons)Nucleus(center of atom;contains protons and neutrons)Orbital shellProton(positive charge)Valence shell(outer shell of atom)C 6+N NN N+N NN N+N N+N N-Figure 2.1 20

8、01 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaElectron Shells in AtomsFigure 2.2 K=2L=8M=18N=32O=32P=10Q=2 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaElectron Shells for Sodium and Chlorine Atoms-Na 11Na 11S

9、odium atomChlorine atomCl 17Cl 17-Figure 2.3 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaEnergy Band Gaps SemiconductorConduction BandValence BandEnergy GapElectron EnergyConduction BandValence Band InsulatorEnergy GapElectron EnergyConduction BandVale

10、nce BandOverlapping bands-little energy is needed for conduction Conductor Electron EnergyFigure 2.4 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaSodium Chloride+Sodium ionA+ion is formed when an atom loses an electron.Na 11Na 11-Chlorine ionA-ion is fo

11、rmed when an atom gains an electron.Cl 17Cl 17-Figure 2.5 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaThe Periodic TableCharacteristics of Commonly Used ElementsIonic BondsCovalent Bonds 2001 by Prentice HallSemiconductor Manufacturing Technologyby Mic

12、hael Quirk and Julian SerdaThe Periodic Table of the ElementsFigure 2.6 Rf104Ha105Sg106Uns107Uno108Une109IAIIAIIIBIVBVBVIBVIIBIBIIBIIIAIVAVAVIAVIIAVIIIAVIIIBHydrogenH1 1.008BerylliumBe49.012Na11Sodium22.989Li3Lithium6.93912 24.312MgMagnesium19KPotassium39.102Ca2040.08CalciumSc21Scandium44.956Ti22Tit

13、anium47.90V23Vanadium50.942ManganeseMn2554.938Fe26Iron55.847Co27Cobalt58.933Ni28Nickel58.71Rh45Rhodium102.91Zn30Zinc65.37As33Arsenic74.922Se34Selenium78.96Br35Bromine79.909Kr36Krypton83.80Al13Aluminum26.981Si14Silicon28.086P15Phosphorus30.974S16Sulfur32.064Cl17Chlorine35.453Ar18Argon39.948B5Boron10.

14、811C6Carbon12.011N7Nitrogen14.007O8Oxygen15.999F9Florine18.998Ne10Neon20.183He2Helium4.0026Rb37Rubidium85.47Sr38Strontium87.62Y39Yttrium88.905Zr40Zirconium91.22Nb41Niobium92.906Molybde-numMo4295.94Cr24Chromium51.996TechnitiumTc4399Ru44Ruthenium101.07Cd48Cadmium112.40Cu29Copper63.54PalladiumPd46 106.

15、4SilverAg47107.87Sm62Samarium150.35Ga31Gallium69.72In49Indium114.82Ge3272.59GermaniumSn50Tin118.69Sb51Antimony121.75Te52Tellurium127.60I53Iodine126.904Xe54Xenon131.30Cs55Cesium132.90Ba56Barium1137.34La57Lanthanum138.91Hf72Hafnium178.49Ta73Tantalum180.95W74Tungsten183.85Re75Rhenium186.2Os76Osmium190.

16、2Ir77Iridium192.2Pt78Platinum195.09Au79Gold196.967Hg80Mercury200.59Tl81Thallium204.37Pb82Lead207.19Bi83Bismuth208.98Po84Polonium 210At85Astatine210Rn86Radon222Uun110Fr87Francium223Ra88Radium226Ac89227ActiniumCe58Cerium140.12Pr59Praseodym-ium140.9160NdNeodym-ium144.24Pm61Prome-thium147EuropiumEu63151

17、.96Gd64Gadolin-ium157.25Tb65Terbium158.92Dy66Dyspro-sium162.50Ho67Holmium164.93Er68Erbium167.26Tm69Thulium168.93Yb70Ytterbium173.0471LuLutetium174.97Th90Thorium232.04Pa91Procat-inium231U92Uranium238.03Np93Neptunium237Pu94Plutonium242AmericiumAm95243Cm96Curium247BerkeliumBk97247Cf98Califor-nium249Es9

18、9Einstein-ium254Fm100Fermium253Md101Mendelev-ium256102NoNobelium253Lr103Lawren-cium257Transition MetalsNonmetalsMetalloids(semimetals)LanthanidesActinides 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaElement Box of the Periodic TableC612.011152.03570347

19、0 s.0.77Carbonatomic weightelectronegativitysymbolacid-baseproperties atomic numbermelting point(C)*boiling point(C)atomic radius()*Based on carbon-12.()indicates the most stable or best known isotope.s.indicates sublimation For representative oxides of group.Oxide is acidic if color is red,basic if

20、 color is blue,and amphoteric if both colors are shown.Intensity of color indicates relative strength.Figure 2.7 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaCharacteristics of Chemicals used in Wafer FabricationContinued on next slideTable 2.1 2001 by

21、Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaCharacteristics of Chemicals used in Wafer Fabrication(continued)Table 2.1 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaIonic Bond for NaClCl-Na+Figure 2.8 2001 by Prent

22、ice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian Serda-Cl 17Cl 17-H 1H 1Hydrogen atomChlorine atomH+Cl HClElectron shared between two atoms to form a covalent bond.Covalent Bond for HClFigure 2.9 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and

23、 Julian SerdaClassifying MaterialsConductorsInsulatorsSemiconductors 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaElectrical Current FlowFigure 2.10 Copper wires provide connections that allow electrons to flow from the-terminal,through the filament ins

24、ide the lamp,and back into the +terminal of the battery.e-6 VoltBatterye-e-e-2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaCopper atomOne electron in the valence ring-Cu 29Cu 29-KLMNFlow of Free Electrons in CopperShell#KLMNTotal#Maximum#e-per shell28183

25、2 60Actual#e-per shell28181 29Figure 2.11 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaHow Sizes Affect ResistanceHigh ResistanceLow Resistance LAR=Figure 2.12 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaA

26、dding an Impurity to Water to Improve its ConductivitySodium and chlorine ions from ordinary table salt provide electrical path for current flow in water.e-e-e-e-+-6 VoltBatteryNa+Cl-H2OFigure 2.13 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaBasic Capa

27、citor StructureK,dielectric constant in farads/cmA,plate area in cm2S,spacing between plates in cmKASC =Formula for Capacitanceconductor (metal plate)conductor(metal plate)dielectric(glass)wire connectionwire connectionSchematic symbol for CapacitorFigure 2.14 2001 by Prentice HallSemiconductor Manu

28、facturing Technologyby Michael Quirk and Julian Serda Battery Charges a Capacitor1.5 VSwitch(+)Positive charged plate(-)Negative charged plateelectrostatic fielde-e-e-e-e-1.5 VBatteryFigure 2.15 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaCapacitor Hol

29、ds a Charge(-)Negative charged plateElectrostatic field1.5 V(+)Positive charged plateFigure 2.16 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaLow-k Dielectric MaterialMetal 2Dielectric material*Metal 1Capacitance*Low K dielectric reduces capacitance bet

30、ween metal layers.Figure 2.17 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaSiliconPure SiliconWhy Use Silicon?Doped SiliconDopant Materialsn-type Siliconp-type SiliconResistivity of Doped Siliconpn Junctions 2001 by Prentice HallSemiconductor Manufactur

31、ing Technologyby Michael Quirk and Julian SerdaSemiconductors Group IVAC,Carbon6Si,Silicon14Ge,Germanium32Sn,Tin50Pb,Lead 82Group IVA Elemental SemiconductorsFigure 2.18 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSi

32、SiSiSiSiSiSiSilicon atoms share valence electrons to form insulator-like bonds.Covalent Bonding of Pure SiliconFigure 2.19 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaSilicon dioxide(SiO2)Silicon waferSiO2 on Silicon WaferFigure 2.20 2001 by Prentice H

33、allSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaDoping of SiliconPSiSiSiSiSiSiPPPPdopant dispenserwaferdopant layerdiffusion of dopant atoms through siliconDeposition StepDrive-in&Diffusion Stepwafer substrateActivationStepFigure 2.21 2001 by Prentice HallSemiconductor Manu

34、facturing Technologyby Michael Quirk and Julian SerdaGroup III(p-type)Boron5Aluminum13Gallium31Indium49Group IVCarbon6Silicon14Germanium32Tin50Group V(n-type)Nitrogen7Phosphorus15Arsenic33Antimony51Acceptor ImpuritiesDonor ImpuritiesSemiconductor*Items underlined are the most commonly used in silico

35、n-based IC manufacturing.Silicon DopantsFigure 2.22 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaDonor atoms provide excess electrons to form n-type silicon.Phosphorus atom serves as n-type dopantExcess electron(-)SiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiS

36、iSiSi P P PElectrons in N-Type Silicon with Phosphorus DopantFigure 2.23 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaConduction in n-Type SiliconFree electrons flow toward positive terminal.Positive terminal from power supplyElectron FlowElectron FlowN

37、egative terminal from power supplyFigure 2.24 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaAcceptor atoms provide a deficiency of electrons to form p-type silicon.+HoleBoron atom serves as p-type dopantSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiSiBSiSiSiSiSiSiBBHole

38、s in p-Type Silicon with Boron DopantFigure 2.25 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaConduction in p-Type SiliconElectron FlowElectron FlowHole FlowHole FlowPositive terminal from voltage supplyNegative terminal from voltage supply+Holes flow t

39、oward negative terminal-Electrons flow toward positive terminalFigure 2.26 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaSilicon Resistivity Versus Dopant ConcentrationRedrawn from VLSI Fabrication Principles,Silicon and Gallium Arsenide,John Wiley&Sons,

40、Inc.Dopant Concentration(atoms/cm3)Electrical Resistivity(ohm-cm)10211020101910181017101610151014101310-310-210-1100101102103n-typep-typeFigure 2.27 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian Serdap-type Sin-type SiCross Section of Planar pn JunctionFigure

41、 2.28 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaAlternative Semiconductor MaterialsTable 2.3 2001 by Prentice HallSemiconductor Manufacturing Technologyby Michael Quirk and Julian SerdaChapter 2 ReviewSummary 41Key Terms41Review Questions42References42