Integrated_Circuits(集成电路)电子信息类专业英语、计算机类专业英语

无锡职业技术学院毕业设计说明书（英文翻译）IntegratedCircuits(集成电路)TheIntegratedCircuitDigitallogicandelectroniccircuitsderivetheirfunctionalityfromelectronicswitchescalledtransistor.Roughlyspeaking,thetransistorcanbelikenedtoanelectronicallycontrolledvalvewherebyenergyappliedtooneconnectionofthevalveenablesenergytoflowbetweentwootherconnections.Bycombiningmultipletransistors,digitallogicbuildingblockssuchasANDgatesandflip-flopsareformed.Transistors,inturn,aremadefromsemiconductors.Consultaperiodictableofelementsinacollegechemistrytextbook,andyouwilllocatesemiconductorsasagroupofelementsseparatingthemetalsandnonmetals.Theyarecalledsemiconductorsbecauseoftheirabilitytobehaveasbothmetalsandnonmetals.Asemiconductorcanbemadetoconductelectricitylikeametalortoinsulateasanonmetaldoes.Thesedifferingelectricalpropertiescanbeaccuratelycontrolledbymixingthesemiconductorwithsmallamountsofotherelements.Thismixingiscalleddoping.Asemiconductorcanbedopedtocontainmoreelectrons(N-type)orfewerelectrons(P-type).Examplesofcommonlyusedsemiconductorsaresiliconandgermanium.PhosphorousandboronaretwoelementsthatareusedtodopeN-typeandP-typesilicon,respectively.Atransistorisconstructedbycreatingasandwichofdifferentlydopedsemiconductorlayers.Thetwomostcommontypesoftransistors,thebipolar-junctiontransistor(BJT)andthefield-effecttransistor(FET)areschematicallyillustratedinFigure2.1.Thisfigureshowsboththesiliconstructuresoftheseelementsandtheirgraphicalsymbolicrepresentationaswouldbeseeninacircuitdiagram.TheBJTshownisanNPNtransistor,becauseitiscomposedofasandwichofN-P-Ndopedsilicon.Whenasmallcurrentisinjectedintothebaseterminal,alargercurrentisenabledtoflowfromthecollectortotheemitter.TheFETshownisanN-channelFET,whichiscomposedoftwoN-typeregionsseparatedbyaP-typesubstrate.Whenavoltageisappliedtotheinsulatedgateterminal,acurrentisenabledtoflowfromthedraintothesource.ItiscalledN-channel,becausethegatevoltageinducesanN-channelwithinthesubstrate,enablingcurrenttoflowbetweentheN-regions.Anotherbasicsemiconductorstructureisadiode,whichisformedsimplybyajunctionofN-typeandP-typesilicon.Diodesactlikeone-wayvalvesbyconductingcurrentonlyfromPtoN.Specialdiodescanbecreatedthatemitlightwhenavoltageisapplied.Appropriatelyenough,thesecomponentsarecalledlightemittingdiodes,orLEDs.Thesesmalllightsaremanufacturedbythemillionsandarefoundindiverseapplicationsfromtelephonestotrafficlights.Theresultingsmallchipofsemiconductormaterialonwhichatransistorordiodeisfabricatedcanbeencasedinasmallplasticpackageforprotectionagainstdamageandcontaminationfromtheout­sideworld.Smallwiresareconnectedwithinthispackagebetweenthesemiconductorsandwichandpinsthatprotrudefromthepackagetomakeelectricalcontactwithotherpartsoftheintendedcircuit.Onceyouhaveseveraldiscretetransistors,digitallogiccanbebuiltbydirectlywiringthesecomponentstogether.Thecircuitwillfunction,butanysubstantialamountofdigital无锡职业技术学院毕业设计说明书（英文翻译）logicwillbeverybulky,becauseseveraltransistorsarerequiredtoimplementeachofthevarioustypesoflogicgates.Atthetimeoftheinventionofthetransistorin1947byJohnBardeen,WalterBrattain,andWilliamShockley,theonlywaytoassemblemultipletransistorsintoasinglecircuitwastobuyseparatediscretetransistorsandwirethemtogether.In1959,JackKilbyandRobertNoyceindependentlyinventedameansoffabricatingmultipletransistorsonasingleslabofsemiconductormaterial.Theirinventionwouldcometobeknownastheintegratedcircuit,orIC,whichisthefoundationofourmoderncomputerizedworld.AnICissocalledbecauseitintegratesmultipletransistorsanddiodesontothesamesmallsemiconductorchip.Insteadofhavingtosolderindividualwiresbetweendiscretecomponents,anICcontainsmanysmallcomponentsthatarealreadywiredtogetherinthedesiredtopologytoformacircuit.AtypicalIC,withoutitsplasticorceramicpackage,isasquareorrectangularsilicondiemeasuringfrom2to15mmonanedge.DependingontheleveloftechnologyusedtomanufacturetheIC,theremaybeanywherefromadozentotensofmillionsofindividualtransistorsonthissmallchip.Thisamazingdensityofelectroniccomponentsindicatesthatthetransistorsandthewiresthatconnectthemareextremelysmallinsize.DimensionsonanICaremeasuredinunitsofmicrometers,withonemicrometer(1mm)beingonemillionthofameter.Toserveasareferencepoint,ahumanhairisroughly100mmindiameter.SomemodernICscontaincomponentsandwiresthataremeasuredinincrementsassmallas0.1mm!Eachyear,researchersandengineershavebeenfindingnewwaystosteadilyreducethesefeaturesizestopackmoretransistorsintothesamesiliconarea,asindicatedinFigure2.2.WhenanICisdesignedandfabricated,itgenerallyfollowsoneoftwomaintransistortechnologies:bipolarormetal-oxidesemiconductor(MOS).BipolarprocessescreateBJTs,whereasMOSprocessescreateFETs.Bipolarlogicwasmorecommonbeforethe1980s,butMOStechnologieshavesinceaccountedthegreatmajorityofdigitallogicICs.N-channelFETsarefabricatedinanNMOSprocess,andP-channelFETsarefabricatedinaPMOSprocess.Inthe1980s,complementary-MOS,orCMOS,becamethedominantprocesstechnologyandremainssotothisday.CMOSICsincorporatebothNMOSandPMOStransistors.ApplicationSpecificIntegratedCircuitAnapplication-specificintegratedcirc