Defects in microelectronic materials and devices

753 Pages·2009·18.863 MB·English

by  D M Fleetwood, Sokrates T Pantelides, Ronald Donald Schrimpf

Defects in
Microelectronic
Materials
and Devices
(cid:1)2008byTaylor&FrancisGroup,LLC.
(cid:1)2008byTaylor&FrancisGroup,LLC.
Defects in
Microelectronic
Materials
and Devices
Edited by
Daniel M. Fleetwood • Sokrates T. Pantelides
Ronald D. Schrimpf
Boca Raton London New York
CRC Press is an imprint of the
Taylor & Francis Group, an informa business
(cid:1)2008byTaylor&FrancisGroup,LLC.
Figure on cover: Z-contrast image of a silicon-silicon dioxide-hafnium dioxide structure showing an isolated Hf atom in
the SiO interlayer (image courtesy of K. Van Benthem and S. J. Pennycook). The expanded image is an electron density
2
plot for this structure (courtesy of A. G. Marinopoulos and S. T. Pantelides).
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Library of Congress Cataloging-in-Publication Data
Fleetwood, Daniel.
Defects in microelectronic materials and devices / Daniel Fleetwood, Sokrates T. Pantelides, and
Ronald D. Schrimpf.
p. cm.
Includes bibliographical references and index.
ISBN 978-1-4200-4376-1 (alk. paper)
1. Microelectronics--Materials--Testing. 2. Metal oxide semiconductor field-effect
transistors--Testing. 3. Integrated circuits--Defects. I. Pantelides, Sokrates T. II. Schrimpf, Ronald
Donald. III. Title.
TK7871.F5485 2008
621.381--dc22 2008018722
Visit the Taylor & Francis Web site at
http://www.taylorandfrancis.com
and the CRC Press Web site at
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(cid:1)2008byTaylor&FrancisGroup,LLC.
Contents
Prefac e
Editors
Contr ibutors
1. D efects in U lt ra-Shallow Junctions
MarkE.Law,RenataCamillo-Castillo,LanceRobertson,andKevinS.Jones
2. H ydrogen-Relat ed Defect s in S ilicon, Germanium,
and Si licon– Germanium Alloys
A.R.Peaker,V.P.Markevich,andL.Dobaczewski
3. Defects in S traine d-Si MOSFETs
YongkeSunandScottE.Thompson
4. The Ef fect o f D efec ts on Ele ctron Transport in Nanome ter-Sca le
Electronic D evices: Im purities and Interf ace R oughness
M.V.FischettiandS.Jin
5. Electrical Char acterizat ion of Defects in Gate Di electrics
DieterK.Schroder
6. Dominating Defects in the MO S System: P and E 0 Centers
b
PatrickM.Lenahan
7. Oxide Traps, Border Traps, and Interf ace T raps in SiO
2
DanielM.Fleetwood,SokratesT.Pantelides,andRonaldD.Schrimpf
8. From 3D Imaging of Atoms to Macroscopic D evi ce Pr operties
S.J.Pennycook,M.F.Chisholm,K.vanBenthem,A.G.Marinopoulos,
andSokratesT.Pantelides
9. D efec t Energy Leve ls in Hf O and R ela ted Hi gh-K Gate Oxides
2
J.Robertson,K.Xiong,andK.Tse
10 . S pe ctro sco pic S tu di es of E lec trically Acti ve Defects i n High- K
Gate Dielectrics
GeraldLucovsky
11. Def ects in CMOS G ate Dielectr ics
EricGarfunkel,JacobGavartin,andGennadiBersuker
(cid:1)2008byTaylor&FrancisGroup,LLC.
12. Negati ve B ias T emperatur e Instabilities in Hi gh-k Gate Dielectrics
M.Houssa,M.Aoulaiche,S.DeGendt,G.Groeseneken,andM.M.Heyns
13. Defect F ormation and Anni hilation in E lectronic Devices
and t he Role of Hydrogen
LeonidasTsetseris,DanielM.Fleetwood,RonaldD.Schrimpf,andSokratesT.Pantelides
14 . T owa rd E ngineeri ng M od eling o f Negative Bias
Temperatur e Instability
TiborGrasser,WolfgangGoes,andBenKaczer
15 . We ar-Out and Time -Depende nt Die lect ric Breakdown
in Sil icon Oxides
JohnS.Suehle
16 . De fects As sociate d with Diel ectri c Bre akdown
in SiO -Based Gate D ielec trics
2
JordiSuñéandErnestY.Wu
17. Defects i n Thin and Ultrathi n S ilicon Dioxides
GiorgioCellere,SimoneGerardin,andAlessandroPaccagnella
18. S tructural Def ects in Si O – Si Caused by Ion B omba rdment
2
AntoineD.Touboul,AminataCarvalho,MathiasMarinoni,FredericSaigne,
JacquesBonnet,andJeanGasiot
19 . Impac t of R adiation- Induced Defec ts on Bi polar Device Oper ation
RonaldD.Schrimpf,DanielM.Fleetwood,RonaldL.Pease,LeonidasTsetseris,
andSokratesT.Pantelides
20. S ilicon Di oxide– Sil icon C arbide Interfaces: Current St atus
and R e cent A dvances
S.Dhar,SokratesT.Pantelides,J.R.Williams,andL.C.Feldman
21 . De fects i n SiC
E.Janzén,A.Gali,A.Henry,I.G.Ivanov,B.Magnusson,andN.T.Son
22. Defects i n Gal lium Arsenide
J.C.BourgoinandH.J.vonBardeleben
Appendix A: Selected High-Im pac t Journal Articl es on Defe cts
in Micr oel ectronic Materials and Devices
(cid:1)2008byTaylor&FrancisGroup,LLC.
Preface
Defects in microelectronic materials can profoundly affect the yield, performance, long-
term reliability, and radiation response of microelectronic devices and integrated circuits
(ICs). This book provides a comprehensive survey of defects in silicon-based metal oxide
semiconductor (MOS) field-effect transistor technologies, which dominate the worldwide
microelectronics marketplace. This book also discusses the defects in linear bipolar tech-
nologies, silicon carbide based devices, and gallium arsenide materials and devices. An
appendix is provided with supplemental material on highly cited papers on defects in
these and other materials systems (e.g., GaN, ZnO, C) that are being investigated
for present and future microelectronics technologies. The chapters described below
summarize decades of experience in characterizing defect properties and their impact on
microelectronic devices, and also look forward to the challenges that will have to be
overcome as new materials (e.g., high-K gate dielectrics and high-mobility substrate
materials) are incorporatedintoincreasingly more highly scaled devicesand ICs.
Chapters1through4focusonyield-andperformance-limitingdefectsandimpuritiesin
the device silicon layer, and=or at the critical Si=SiO interface. In Chapter 1, Law et al.
2
discuss yield-limiting defects that are important to control in highly scaled technologies
withultra-shallowjunctions.Theimpactofdefectsondiffusionandactivationprocessesis
emphasized.DefectsinSi,Ge,andSiGealloysassociatedwithhydrogenarediscussedby
Peaker et al. in Chapter 2. The incorporation of hydrogen and its complexes in these
materials are reviewed in detail, with examples provided from a broad range of experi-
mental and theoretical work. In Chapter 3, Sun and Thompson describe dislocations in
transistors that have been designed with highly strained layers to enhance carrier mobi-
lities. In Chapter 4, Fischetti and Jin discuss the effects of ionized dopant atoms and
interface roughness on electron transport in very highly scaled devices and ICs. An
extensive review of mobility-limiting scatteringprocesses is presented.
Chapters 5 through 8 describe electrical, analytical, spectroscopic, and state-of-the-art
microscopic methods to characterize defects in MOS gate oxides. In Chapter 5, Schroder
providesa comprehensive review of electricaland analytical techniques to estimate dens-
ities and energy distributions of defects in MOS gate dielectrics and=or at the Si=SiO
2
interface. A wide variety of examples are provided. These enable a comparison of the
relative advantages and limitations of different characterization methods. In Chapter 6,
Lenahan provides an extensive review of electron spin resonance studies that have pro-
videdsignificantinsightintothemicrostructureofthedominantSiO holetrap.Thisisthe
2
0
E defect,atrivalentSicenterinSiO associatedwithanOvacancy.Thedominantdefectat
2
the Si=SiO interface is also characterized extensively; this is the P defect, a Si dangling
2 b
bond that frequently is passivated by hydrogen during device processing, but when
depassivated after electrical stress or ionizing radiation exposure can function as an
interface trap. In Chapter 7, the properties of oxide and interface traps are reviewed by
Fleetwood et al., with particular emphasis on separating the effects of ‘‘true’’ oxide and
interfacetrapsfromtheeffectsofnear-interfacialoxidetrapsthatexchangechargewiththe
Si on the timescale of typical device measurements (border traps). Thermally stimulated
current and low frequency noise techniques are described to estimate oxide and border
trapdensitiesandenergydistributions.InChapter8,Pennycooketal.presenttheresultsof
(cid:1)2008byTaylor&FrancisGroup,LLC.
aberration-corrected scanning transmission electron microscopy on MOS structures; these
techniques provideinformation on defects and impurities withsub-angstromresolution.
Chapters9through11focusondefectsinhigh-dielectricconstant(high-K)materialsthat
are under intense development to replace SiO (more precisely, nitrided SiO ) as the
2 2
preferred gate dielectric material for Si-based ICs at or beyond the 45 nm technology
node.InChapter9,Robertsonetal.describetheoreticalcalculationsofdefectenergylevels
in high-K dielectrics, where it is found that the O vacancy is the main electrically active
defectinHfO -basedhigh-Kgatedielectrics.InChapter10,Lucovskysurveysanextensive
2
amount of spectroscopic data on transition metal oxides. These materials are compared
and contrasted with SiO , and a critical review of the suitability of these materials is
2
provided for incorporation into device manufacturing. In Chapter 11, Garfunkel et al.
review experimental results and computational calculations of defects in HfO -based
2
gate stacks. The effects of thesedefects on deviceelectricalproperties are emphasized.
In Chapter 12, Houssa et al. survey negative bias temperature instabilities (NBTIs) for
high-K materials, and they separate the effects of interface and bulk traps on device
electrical response. In Chapter 13, Tsetseris et al. discuss the role of hydrogen in NBTI in
SiO ,andsummarizefirst-principlescalculationsofdefectformation,defectdynamics,and
2
defect annihilation in theSi=SiO system. Acomprehensiveengineering model ofNBTIis
2
developedbyGrasseretal.inChapter14.Theeffectsofpoststressrelaxationareshownto
be important to a complete understanding of the underlying mechanisms, as well as in
developing techniques to predict device lifetimes from accelerated measurements.
Chapters15through18discussdefectsinultrathinoxides(SiO andsiliconoxynitride).
2
In Chapter 15, Suehle describes the role of defects and hydrogen in SiO on the time-
2
dependent dielectric breakdown of MOS devices and ICs. The present understanding of
defect generation processes is discussed, as are statistical models for the resulting device
failure distributions. Defects associated with dielectric breakdown and conduction in
oxides degraded by long-term, high-field stress are discussed in detail by Suñé and Wu
in Chapter 16. The percolation model of breakdown is described, and the relative roles of
holesandhydrogeninthebreakdownprocessareevaluatedexperimentallyandanalytic-
ally. The effects of radiation and stress-induced defects in thin oxides are described by
Cellere et al. in Chapter 17 and Touboul et al. in Chapter 18. Cellere et al. emphasize
processes that lead to radiation and stress-induced leakage currents, which are especially
importantfornonvolatilememorycellsthatcanbedischargedviaextremelylowcurrents,
andToubouletal.discussthephysicaldamagecausedbyahighenergyionwhenitpasses
through a dielectric layer. The latter is of particular concern for the reliability of space
systems.
The effects of radiation-induced defects on linear bipolar devices are discussed by
Schrimpf et al. in Chapter 19. Even though similar defects are formed in the base oxides
of linear bipolar transistors as in MOS structures (primarily oxide and interface-trap
charge), the effects of these charges on device operation can be quite different for linear
bipolar transistors than for MOS devices. One example of this is enhanced low-dose-rate
sensitivity, which is the excess buildup of (primarily) interface traps during low-electric-
fieldirradiationsoftypicalbaseoxidesthatcanbeaffectedbytrapdensitiesandhydrogen
concentrations of the structures.
In Chapter 20, Dhar et al. present an overview of defects in oxides on SiC wafers. The
highergrowth temperaturesand thediffering interfacial layersforSiC,relativetoSi,lead
tosignificantdifferencesindefectproperties.Mostnotably,dangling bonddefects cannot
bepassivatedaseasilyattheSiC=SiO interfacewithhydrogentreatmentasfortheSi=SiO
2 2
interface.AcomprehensivesurveyofdefectsinSiCisprovidedbyJanzénetal.inChapter
21.Anextensivearrayofexperimentaldataandtheoreticalcalculationsaretabulatedand
discussed in detail. Defects in GaAs are reviewed by Bourgoin and von Bardeleben in
(cid:1)2008byTaylor&FrancisGroup,LLC.
Chapter 22. Particular emphasis is placed on As antisite defects associated with the EL2.
Finally,theappendixlistsalargenumberofhighlycitedjournalarticlesrelatedtodefects
in the Si=SiO system, high-K dielectrics, GaAs, GaN, and ZnO. Brief synopses are pro-
2
vided of more than 450 highly cited articles; the interested reader can use these reference
listsasastartingpointtoobtainmoreinformationonthenatureandeffectsofdefectsand
impurities in these or othersemiconductor-based materialsystems.
Thisbookwasencouragedbytheprogrammanagersoftwomultidisciplinaryuniversity
research initiatives (MURIs) sponsored by the Air Force Office of Scientific Research,
Gerald Witt and Kitt Reinhardt, on the effects of ionizing radiation on microelectronic
materials and devices. We appreciate their support during these programs, as well as the
efforts of all of our MURI collaborators—you will see many of their contributions in this
book,aswellascontributionsfrommanyotherexpertsinthefieldwhograciouslyagreed
to provide chapters in their fields of specialty. We also wish to thank all our valued
professional colleagues, research collaborators, and sponsors who have contributed so
much to these efforts, as well as Jill Jurgensen, Allison Shatkin, and Shelley Kronzek at
Taylor&Francisfortheirinterestinandassistancewiththisbook.Wefinallywishtothank
Arun Kumar, Jennifer Smith, and the entire production team for their strong and timely
support.
Daniel M. Fleetwood
Sokrates T. Pantelides
Ronald D.Schrimpf
Nashville,Tennessee
(cid:1)2008byTaylor&FrancisGroup,LLC.