晶體管本底數(shù)據(jù)

Therearenumerousmethodsformeasuringtemperatureofanoperatingsemiconductordevice.測(cè)量工作中的半導(dǎo)體 methodscanbebroadlyplacedintothreegenericelectrical,optical,andphysicallycontacting.這些辦法能夠歸納為三種： fundamentalsunderlyingeachofthecategoriesarediscussed,andareviewofthevarietyoftechniqueswithineachis Someoftheadvantagesanddisadvantagesasasthespatial,time,andtemperatureresolutionareKeywords核心詞Electrical,measurements, optical,semiconductor,temperature電學(xué)辦法，測(cè)量，光學(xué)辦法，半導(dǎo)體，溫度Introduction'Operating'temperaturehasimportantconsequencestheperformanceandreliabilityofsemiconductordevices. instance,thespeed,ormaximumoperatingfrequency,ofmicroprocessortypicallydecreasesasthetemperatureincreases,andthegainortransconductanceofatransistormayeitherincreaseordecreasewithincreasingtemperature,dependinguponthedevicetypeandoperatingconditions.環(huán)境。Itisalsocommonlyassumedthatthesafetymarginorreliabilityofasemiconductordevicedecreasesasthetemperatureincreases.Itisnotsurprisingthen,thatasignificantamountofeffortgoesintoaccuratelymeasuringthetemperatureatwhichdevicesoperate.因此應(yīng)當(dāng)在器件溫度測(cè)量的方面投入大量的努Thetopicofmeasuringthetemperatureofsemiconductordevicesisinmanyways'mature'inthatpeoplehavebeentryingtomeasurethetemperatureof semiconductordevicesfromthetimeoftheinventionofthe 以來，測(cè)量溫度就是人們考慮的主題。Itremains,though,averyrelevanttopicinthatpeoplearestillinventingnewmethodstoaddresstemperaturemeasurement現(xiàn)在仍然如此，并且這方面更加引發(fā)人們的關(guān)注。issuesthatpreviouslyhadnosolutionsandbecausethermalmanagementandtemperaturecontrolareprobablymoreofaconcerntodaythaneverbefore[1-3]. Moore'slawdictatesthatdevicesandcircuitswillcontinuetoshrinkinsize,bepackedmoredensely,operateathigherswitchingspeeds,anddissipatemorepoweroverall[4].并且會(huì)有更快的運(yùn)行速度，和更大的功率。ThemajortemperaturechallengesassociatedwiththeseadvancesincludeimprovementsinthespatialandtemporalresolutionoftheTheactof'measuring'thetemperatureisinrealitythemeasurementofsomephysicalphenomenawhichitselfisaffectedorchangedbytemperature.溫度有關(guān)的物理量的變化。Thephysicalbywhichthetemperatureofadevice'makesitselfknown'aremanyandvaried,andthusawiderangeofmethodshavebeenemployedformeasuringandpredictingthetemperaturewhichdevicesoperate. 因此而產(chǎn)生的測(cè)量溫度的方式也是諸多的。Forsemiconductordevices,theusefultemperaturemeasurementmethodscanbedividedintothebroad,genericcategoriesofelectricalmethods,opticalmethods,andphysicallycontactingmethods.量關(guān)聯(lián)辦法。Inthefirsttwocategories,thetemperaturevariationofsomepropertyofthedevice(anelectricaloropticalproperty)isusedasa 度原則。Inthethirdcategory,atemperaturetransducer(suchasathermocouple)assumesthetemperatureofthedevicethroughintimatecontact,anditisthetemperatureofthetransducerthatisactuallymeasured.Itistheintentheretobrieflyreviewanumberofcommonlyusedandusefulmethodsformeasuringdevicetemperature.這是對(duì)某些有用的測(cè)量溫度辦法的回憶。Thebasisunderlyingthewillbepresented,someindicationofaccuracyandspatialandtemporalresolutionwillbeprovided,andanyspecialrequirementsorprecautionsassociatedwitheachmeasurementwillbediscussed.GenericTherearemanydifferentwaystomeasuretemperatureswithinasemiconductordeviceorcircuit.測(cè)量半導(dǎo)體器件或電路溫度的辦法有諸多個(gè)。AwidevarietyofelectricalandopticalphenomenaassociatedwithsemiconductormaterialsandthedevicesfabricatedfromthemaretemperaturesensitiveandcanbeusedasAlsothereareavarietyoftransducersthatwhenincontactwiththedevicecanbetoindicatethetemperatureof thedevice.同時(shí)，有諸多的和器件有關(guān)聯(lián)溫度傳感器能夠用于器件溫度的檢測(cè)。Inthefollowing,eachofthegenerictypeswillbedescribedbrieflylookinglateratmorespecificmethodsbelongingtoeachtype.OpticalTousetheopticalproperties asathermometer,eithernaturallyemittedradiation,reflectedradiation,orstimulatedemittedradiationismeasured.Asanexample,anopticalbeam(ofphotons)isfocusedatapointonthedevice,andtheincidentphotonswill interactwiththedeviceintheregionofthepointoffocus.(Ifthereisnointeraction,thenthephotonswilltravelunimpededthroughtheobject,andtheobjectistransparenttothephotons-asituationthatisuninterestingforourdiscussion.) 過介質(zhì)，這種狀況不是我們討論的）Oneinteractionamongseveralthatmayoccuristhatsomefractionoftheincidentphotonswillbereflected,orscatteredback,fromthesurface(orfromathinsurfaceregion)oftheobject.光子會(huì)被反射，并且分散開。Thereflectionorscatteringresultsfromacomplicatedinteractionbetweentheincidentphotonsandthelatticephonons(andmaybetheelectrons)of objectbeingprobed.產(chǎn)生與光子和晶格互相作用的散射和反射 distributioninenergyofthelatticephononsisastrongfunctionofthelocaltemperatureoftheobject,andthenetresultofthephoton-phononinteractionisthattherelativenumber,andmaybetheenergyandphaseofreflectedphotons(withrespecttotheincidentphotons),changeswithtemperatureofthe Clearly,ifthesechangescarefullymeasured,theymightbeusedtoinferthetemperatureoftheprobedobjectintheregionofthepointbeing 局部溫度的探測(cè)。Opticalmethodscanbeconsideredtobenon-contactinginthesensethatonlyphotonsinteractwiththedevice,andtheeffectonthedeviceoperationortemperatureduetotheinteractioncanusuallybeneglected.光學(xué)測(cè)量法Spatialresolutionofopticalmethodsisdeterminedbythesizeoftheopticalprobeandtheregionoverwhichitinteractsthedevice.與之發(fā)生互相作用的半導(dǎo)體器件面積。Thetimeresponseisdeterminedultimatelybytheresponsetimeoftheopticalphenomenatochangestemperature,butalsopracticallybyinstrumentationresponse.響應(yīng)時(shí)間取Advantagesofopticalmethodsincludethattheycanhaveveryhighspatialresolution,canoftenmeasurevariationsintemperature,andarenon- temperaturemapsofthesurfaceofadevicecanusuallybeeasilymadefromamatrixofmeasurements. arethatonemusthaveopticalaccesstothedevice,somethingnotusuallypossibleifthedeviceispackaged,andtheequipmentrequiredisoftenexpensiveanddifficulttouse.ElectricalManyoftheelectricalpropertiesofsemiconductorandcircuitscanbestrongfunctionsoftemperature.許多半導(dǎo)體器件的電junctionforwardvoltage,thresholdvoltage,leakagecurrentandgain,tonamebutafew,areexamplesofelectricaltemperaturesensitiveparametersTSP).measurementofanyofthesequantitiescanalsobeusedinferthetemperatureofanoperatingsemiconductor[5].對(duì)于這些物理量的測(cè)量能夠用于檢測(cè)器件的溫度。Thereare andconceptualdifferences,though,betweentheseelectricalmeasurementsoftemperature,andthepreviouslydescribedopticalprobe Conceptuallyatleast,theopticalprobecanmadeverysmallandthusbeusedtoprobethetemperatureaverysmall,welldefined regionofthedevice.原則上，光學(xué)檢測(cè)能夠 Apoint-by-pointmapofthetemperatureatdifferentpositionsondevicemightevenbemade.各個(gè)位置溫度點(diǎn)的不同都能夠精確的做出Electricalmethods, bytheirverynature,lumped,oraveraging,methods.Forinstance,thevoltageofapn-junctionataconstantcurrentisknowntowithtemperatureinapredictableway. 例如，pn結(jié)電壓隨著溫度會(huì)精確的變化。Thus,theforwardvoltagecanbeusedtoinferthetemperatureofthebutnotnecessarilythetemperatureanywhereelseinthedevice.能夠用來測(cè)量結(jié)電壓，但是不能精確測(cè)量器件其它區(qū)域的電壓。Ininstances,thedevicetemperatureisthesameeverywhere;therefore,thisisoflittleconsequence.諸多狀況下，Howeverinotherinstances,thisisnotthecase.然而，有些狀況下，器件溫度分布不均勻，各個(gè)區(qū)域溫度很大不同。Eventhejunctiontemperaturemaynotbethesameeverywhereinthejunction.即使是結(jié)溫度也有很大不同。 Themodelusedtodeterminethevariationoftheforwardvoltageofajunctionwithtemperatureshouldbeconsidereda'lumped'modelinthatthedistributednatureoftheelectricalandthermalbehaviorofthejunctionislumpedintoamodelwithasingle singlevoltage,singlecurrent Althoughelectricalmethodssacrificesomespecificityofthemeasuredtemperature,theiradvantageisthatnospecialsamplepreparationisrequiredbecauseallthenecessaryelectricalconnectionsarealreadyavailable,sincetheyarerequiredfornormaldeviceoperation. Electricalmethodsarethusconsideredtobenon-contactingbecausetheelectricalcontactsrequiredtomakethemeasurementarethosealreadyrequiredforthedevicetooperate.Thespatialresolutionofelectricalmethodsisdifficulttodetermine.Asevidencedfromthediscussionabove,thetemperatureindicatedissomelumpedtemperatureoftheactualtemperaturedistribution. 測(cè)的溫度為事實(shí)上溫度分布的平均溫度。Thetimeresolutionispracticallydeterminedbyinterferencesandparasiticeffectsthatwillbediscussedlater.時(shí)間分辨率Advantagesofelectricalmethodsarethattheyarenon-contactingandaretheonlytypethatcanbemadeonpackageddevices. 要直接接觸器件，故而能夠測(cè)量已經(jīng)封裝完畢的器件。Themajordisadvantagesarethefactthatthespatialresolutioncannotusuallybewelldeterminedandthatonlyasingle,averaged temperatureismeasuredforadevicethatusuallyhassometemperaturedistribution(i.e.,temperaturemapscannotbemade).2.3. PhysicallyContactingMethodsthatrelyonphysicallycontactingthedeviceincludepointcontacting,suchasthermocouplesandscanningthermalprobes,andmultiplecontactingorblanketcoatings,suchasliquidcrystalsandthermographicphosphors. Allrelyuponatransferofthermalenergy,orheat,fromthedeviceofinteresttotheobjectcontactingthedevice,thethermometer.Thenatureofthatenergytransferandthepossibleeffectonthedevicetemperatureofconductingheatfromthedeviceareimportantconsiderationswiththesemethods. resolutionforcontactingmeasurementsaredeterminedbythesizeoftheprobeorcoatingparticlesbeingused,andtimeresponsedependsuponthethermalresponsetimesoftheprobeorparticles. Advantagesofcontactingmethodsarethattheycanhaveverygoodspatialresolution,lessthan100nminsomeinstances,and,liketheopticalprobes,temperaturemapscanbemade.Temperaturemapsrequireamatrixofmeasurementsforthepointcontactmethodsandareaninherentfeatureintheblanketcoatingmethods.Disadvantagesarethefactthatthesurfaceofthedevicebeingmeasuredmustbeavailable forcontacting(thuspackagedchipscannotbemeasured)andthethermalresponsedependsupontheresponseoftheprobe,whichmaybeconsiderablyslowerthanthatofthedevice.Thishasbeenintendedasanintroductiontothegenericmethodsthatcanbeusedtomeasurethetemperatureofanoperatingsemiconductordevice. Insummary,therearemethodsthatuse:i)anopticalprobe, ii)temperaturesensitiveelectricaldeviceparameters,or iii)aphysicallycontactingprobetomeasurethetemperature. TableIshowssomeofthecharacteristicsandrelativeadvantagesanddisadvantagesofthegenerictypesofmeasurements. Inthefollowingsections,moredetaileddiscussionisgivenofspecificmethodsofeachgenerictype.Blackburn,TemperatureMeasurementofSemiconductor...ElectricalElectricalmethodsformeasuringtemperatureareattractivebecausetheycanbemadeonpackageddevices;i.e.,visualormechanicalaccesstothechip isnotrequired. Themajordisadvantageisthatonlya representativeaveragechiptemperaturecanusuallybedeterminedandtemperaturemapscannotbemade. Amajorconcernwiththeuseofelectricalparametersasthermometersistheseparationoftheeffectstemperaturefromtheinherentelectricalvariationsofthese Asanexample,foradiode,whenthecurrentisincreasedthetemperaturewillalsoincrease(duetotheincreasedpowerdissipation). Theeffectsonthediodevoltagewillbethatthevoltagewilltendto increaseduetotheincreasingcurrent,butitwillalsotendtodecreaseduetotheincreasingtemperature. Theelectricaleffectmustbeisolatedoreliminatedtousethetemperaturevariationofthevoltageasathermometerforthediode.Anotherconcernwithelectricalmeasurementsisthecalibrationprocess. Aswith alltemperaturemeasurements,theelectricalparameterthatistobeusedasthethermometermustbecalibratedwithrespecttotemperature. Calibrationisusuallyperformedbysettingthedevicetoaseriesofknowntemperatures(e.g.,byusingatemperature-controlledovenorhotplate,thetemperatureofwhichismeasuredwithathermocouple)andmeasuringtheelectricalparameterwhilethedeviceissettoeachtemperature. Itisassumedthatthedeviceisatthesametemperatureastheovenorhotplate. non-electricalmethods,thereisnoselfheatingofthedeviceduringcalibration,andalloftheheatisbeingsuppliedexternallybytheovenorhotplate. Itisusuallyaverygoodassumptionthatthetemperatureofthehotplateorovenisthesameasthedevicetemperaturewhennoselfheatingis Forelectricalmeasurements,though,bynecessity,heatisdissipatedwithinthedeviceduringthecalibrationprocessbecausesomeheatisalwaysdissipatedbythedevicewhenitiselectricallyactive.SwitchedandNon-SwitchedMea