Materials and Reliability Handbook for Semiconductor Optical and Electron Devices PDF
Preview Materials and Reliability Handbook for Semiconductor Optical and Electron Devices
Materials and Reliability Handbook for Semiconductor Optical and Electron Devices Osamu Ueda (cid:129) Stephen J. Pearton Editors Materials and Reliability Handbook for Semiconductor Optical and Electron Devices Editors OsamuUeda StephenJ.Pearton GraduateSchoolofEngineering UniversityofFlorida KanazawaInstituteofTechnology Gainesville,FL32611,USA Tokyo,Japan ISBN978-1-4614-4336-0 ISBN978-1-4614-4337-7(eBook) DOI10.1007/978-1-4614-4337-7 SpringerNewYorkHeidelbergDordrechtLondon LibraryofCongressControlNumber:2012947361 #SpringerScience+BusinessMediaNewYork2013 Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpartof the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation,broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,andtransmissionor informationstorageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilar methodologynowknownorhereafterdeveloped.Exemptedfromthislegalreservationarebriefexcerpts inconnectionwithreviewsorscholarlyanalysisormaterialsuppliedspecificallyforthepurposeofbeing enteredandexecutedonacomputersystem,forexclusiveusebythepurchaserofthework.Duplication ofthispublicationorpartsthereofispermittedonlyundertheprovisionsoftheCopyrightLawofthe Publisher’s location, in its current version, and permission for use must always be obtained from Springer.PermissionsforusemaybeobtainedthroughRightsLinkattheCopyrightClearanceCenter. ViolationsareliabletoprosecutionundertherespectiveCopyrightLaw. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publicationdoesnotimply,evenintheabsenceofaspecificstatement,thatsuchnamesareexempt fromtherelevantprotectivelawsandregulationsandthereforefreeforgeneraluse. While the advice and information in this book are believed to be true and accurate at the date of publication,neithertheauthorsnortheeditorsnorthepublishercanacceptanylegalresponsibilityfor anyerrorsoromissionsthatmaybemade.Thepublishermakesnowarranty,expressorimplied,with respecttothematerialcontainedherein. Printedonacid-freepaper SpringerispartofSpringerScience+BusinessMedia(www.springer.com) Preface Thishandbookcoversreliabilityproceduresandapproachesformodernelectronic andphotonicdevices,includinglasersandhigh-speedelectronicsusedinallaspects ofourlives,fromcellphonestosatellites,datatransmissionsystems,anddisplays. Reliability offers significant experimental and modeling challenges. Typically, parts cannot betested until they fail under normal operatingconditions.Since the target is frequently a decade or longer of useful life, this is impractical. Conse- quently, accelerated testing is performed. This procedure only works when the physicsiswellunderstood,andthefailuremechanismisnotacceleratedbyfactors notunderthecontrolofthetesting.Modelingofthefailuremechanismiscrucialin making extrapolated predictions of lifetime. Computer-Aided Design tools have advancedtothepointwheremultiplefactorsinfluencingreliabilitycanbeincluded intestingsimulations. Lifetime prediction for compound semiconductor device operation is notori- ously inaccurate due to the fragmented efforts in reliability and the absence of standardprotocols.Engineershaveusuallyreliedonacceleratedtestingatelevated temperaturewithextrapolationbacktoroom-temperatureoperation.Thistechnique frequentlyfailsforscaled,high-current-densitydevices.Devicefailureisdrivenby electric field or current mechanisms or low activation energy processes that are masked by other mechanisms at high temperature. Device degradation can be drivenbyfailureineitheractivestructuresorpassivationlayers. In this handbook, we have attempted to provide comprehensive coverage of reliabilityengineeringforIII-Vdevicestructures,includingmaterialsandelectrical characterization, reliability testing, and electronic characterization. These latter techniques are used to develop new simulation technologies for device operation and reliability. In turn, these techniques allow accurate prediction not only of reliability but also the ability to design structures specifically for improved reliability of operation. While the characterization and accelerated testing and diagnostics isolate the factors controlling reliability, the simulation capability based on the characterization results can help to predict and better explain device reliability.Therefore,thereisextensivefeedbackbetweentheseapproaches. v vi Preface ThebasicunitoffailureinSidevicetechnologyistheFIT(failureunit),defined as 1 failure/109 device hours. For 100 devices on test, a failure rate of 1,000 FIT would mean there would be only 1 failure in 1 year. Given that a relatively small number of devices will actually show failure, it is critical to both enhance the failure rate through accelerated testing (the five common stresses used are temperature, voltage, current, humidity, and temperature cycling) and treat the resultingreliabilitydatacorrectly.Inanystudyunderacceleratedagingconditions, different failure mechanisms may be accelerated by different amounts for the sameappliedstress.Acceleratedagingisusefulonlyifweknowthefailuremecha- nism. In Si MOS devices, time-dependent failure mechanisms include surface chargeaccumulationorinjection,dielectricbreakdown,electromigration,andcon- tactdegradationandcorrosionduetocontamination.Incompoundsemiconductors, we have the added issues of local regions of nonstoichiometry that affect field distributions and increase recombination, oxidation of AlGaAs or AlGaN, high densities of dislocations, and other extended defects in some structures and high surfacestatedensities. WealsocoverstandardSireliabilityapproachestodeterminetheinstantaneous failure rate and mean time to failure and therefore the distribution functions most relevanttothespecificdevicetechnology.ItisexpectedthattheWeibulldistribu- tionisthemostrelevant,sincethefailureratewilllikelyvaryassomepowerofthe ageofthedevice.Inthiscase,thefailurerate,l(t),isgivenby lðtÞ¼ðb=aÞtb(cid:2)1 whereaandbareconstants.Forb > 1,thefailurerateincreaseswithtime,which is likely for compound devices, as defect migration or creation and oxidation orcontactdegradationoccur.Intheearlypartofreliabilitystudies,Duaneplotting is also relevant to allow a quick prediction of failure rates when the number of devicefailuresislow.Inthisapproach,thelogoftheaveragefailurerate(fraction of failed devices at time t divided by the time) is plotted as a function of the log of time. The log-normal distribution function is a more general approach for describing the failure statistics over wide spans of time. It may also be the case thattherewillbetwoormorefailurepopulationsduetothepresenceofmorethan one failure mechanism. This can be resolved on a log-normal distribution that revealsthedifferenttimedependenceofthevariousfailuremechanisms. This handbook focuses attention on voltage and current acceleration stress mechanisms. Many studies in Si indicate that the reaction rate of the failure mechanism is proportional to a power of the applied voltage as well as temperature,i.e., RðT;VÞ¼ROðTÞVgðTÞ where the coefficient RO(T) is an Arrhenius function of T and the power depen- dence varies between 1 and 4.5. This determines how much acceleration occurs with increases in the bias voltage during stressing. If dielectric breakdown is the Preface vii dominantfailuremode,thenatagivenfield,afractionofthedeviceswillfailina shorttime,withnoadditionalfailuresuntilanincreasedfieldisapplied. Part1ofthisbookcoversopticaldevicessuchaslight-emittingdiodes(LEDs) and laser diodes (LDs) including conventional edge-emitting lasers (or edge emitters) and vertical-cavity surface-emitting lasers (VCSELs). Since the earliest stages in the history of R&D of III-V optical devices (mid-1960s), long-term reliability has been one of the key issues. This part of the book provides overall featuresoflifetestingofoptical devicesandresultsforvarious changes indevice characteristics corresponding to a variety of device degradation modes or root causes. In order to clarify the physical phenomena occurring in the degraded regions, one must do various failure analyses on the degraded devices. In this part, detailed modern failure analyses for optical devices are systematically presented. Concerning the degradation, three major failure (degradation) mechanisms are distinguished as follows: classical rapid degradation due to “dark-line defects (DLDs)formation”andrecombination-enhanceddislocationmotion,gradualdeg- radationduetorecombination-enhancedpointdefectreactionwhichdeterminesan ultimatelifetimeofthediodes,andcatastrophicfailure(catastrophic optical dam- age(COD)incaseofedgeemitters).Otherdegradationmodessuchasdegradation due to ESD/EOS, acceleration of gradual degradation due to local lattice strain, degradationpeculiartohigh-powerlaseroperation,etc.,arealsodescribed.Itisalso worthyofnotethatthebookfocusesindetailonmaterialsissuesanddegradationof InGaN/GaN LDs. The VCSEL chapter is also informative for those working on reliabilitystudiesaswellastheR&DofVCSELchipsand/orcomponentsinwhich VCSELs are used as key devices. Fundamental physics buried in the degradation phenomena,i.e.,theoryonrecombination-enhanceddislocationglide(REDG)and recombination-enhanceddefectreactions(REDR),aresystematicallyreviewedby professionalsinthisparticularfield. Thesecondpartofthebookfocusesonelectricaldevicessuchasheterojunction bipolartransistors(HBTs)andhighelectronmobilitytransistors(HEMTs).Thereis tremendouscurrentinterestindeterminingthedegradationandfailuremechanisms of short gate length high electron mobility transistors in the AlGaN/GaN and AlGaAs/GaAs systems under athermal, voltage, or current-driven conditions and innewmethodologiestopredictandmitigateagainstdevicefailureunderpractical operating conditions. The failure mechanisms have typically involved factors such as metal contact reaction with the semiconductor or insulation on a local scale near the high-field regions between the gate anddrain, ora new mechanism called the inverse piezoelectric effect in which high biasing leads to lattice distortions and eventually formation of cracks that can then be oxidized or filled with metal by migration from the contacts. The presence of such failure mechanisms means that local probes for determining compositional and bonding changes on a local scale near the contacts are needed. Ultimately, the need is to determinethemechanismsfortheobservedincreasesindevicecurrentatthreshold valuesofelectricfield,andthenprovidethatinformationtoasimulationcodeused forpredictingfailure. viii Preface In sum, this book is the first to cover all aspects of compound semiconductor devicereliability.Researchresultsonreliabilityandmaterialsissuesofbothoptical and electrical devices since 2000 are systematically described. Readers will find characterizationtechniquesneededtounderstandfailuremechanismsincompound semiconductor devices, the statistics and experimental approaches to reliability studies, and finally case studies of laser degradation and HEMT degradation amongthekeybenefits. Tokyo,Japan OsamuUeda Gainesville,FL,USA StevePearton Acknowledgements TheeditorswishtothankSaraKateHeukerottandDavidPackerofSpringerUSfor guidingthisprojecttocompletion.MuchoftheworkatUFwassupportedinpartby anAirForceOfficeofScientificResearchMultiDisciplinaryUniversityResearch InitiativemonitoredbyJimHwang. Prof.OsamuUeda,KanazawaInstituteofTechnology,Japan Prof.StevePearton,UniversityofFlorida,Gainesville,FL32611,USA ix
The list of books you might like
