SELFASSEMBLEDMONOLAYERS

SAMSanatomy

2

• Headgroup– Affinity tosubstratetoinducechemisorbed

surfacereactions– Highenergychemicalbound (100kJ/mol)

providesmolecularstability(thermal,chemical,mechanical)

• Tailgroup– Closed-packedstructuredrivenbyVander

Waalsinteractionbetweenalkylchains• EndorFunctionalgroup

– Definesproperties ofmonolayer,e.g.,hydrophobicity/hydrophilicity, affinitytoanchorwithbiologicalentities

Substrate

Assembly

Order

End group

Tail

Head Group

Functionalization

Singleorganicmonolayerfromorderedmolecular2Dassemblyformedspontaneouslybythechemisorptionoftheheadgroup

SAMSprecursors

q Keyselectioncriteria

§ Headgroupdeterminedbysubstrate§ Thiols(organosulfurs) formetals§ Silanesfor(trichlorosilane,alkylsilane)foroxides

§ Phosphonates, carboxylates…

§ Functionalgroup§ Non-polarhydrophobic: e.g.,-CH3

§ Polarhydrophilic: -OH,-COOH

3

Thiols forSAMsonAusurfaces

Silanes onoxidesurfacesDiBenedetto,S.A.,etal.,Adv.Mater.,2009.21(14-15):1407-1433.

SilaneSAMS

4

FOTS FDTS DTS

Name Tridecafluorotetrahydrooctyltrichlrosilane

Heptadecafluorotetrahydrodecyltrichlrosilane

Dodecyltrichlorosilane

Formula C8H4Cl3F13Si C10H4Cl3F17Si C12H25Cl3Si

Gelest# SIT8174.0 SIH5841.0 SID4630.0

Price $28/10g $84/10g $10/10g

B.P. 84˚C 216˚C 120˚C

Vap.Pr. 4.2Torrat70˚C 1.7Torrat80˚C 0.5-1Torr@100˚C

APPLICATIONS

5

Applications

q Wettingcontrol(hydrophobic,hydrophilic,oleophobic)

q Friction/anti-stiction/lubricationq Nanostructurefunctionalizationq Buildingblocksforheterostructuresq OLED/Flexibleelectronicsq Celladhesion/proteinadsorption

6Ultratech,FDTSonPtALD(119˚)

Teshima,K.,etal.,Langmuir,2003.19(20):p.8331-8334.

HydrophobicSAMonoxide Biologicalassays Gaspermeationbarrier

Gurard-Levin,etal..AnnualRev.ofAnalyt.Chem.,2008.1:p.767-800.

Asayandal.,Tribol.Lett.,2008.29(1):p.67-74.

MEMSanti-stictioncoating

FOTSonCotton

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Ink

Oil

After5-10s After1hour

NoSAM SAM OilInk Water

t=0min t=10min t=120min

Deposition inSavannahS200at80˚C,10min.exposure

In-situQCMduringALDonSAMS

q In-situQCMmeasurementsduringoxidegrowthbyALDonvapor-depositedalkanethiols

q Study inSavannahS200withQCMintegratedinlid

q VapordepositedSAMSachieveALDinhibition inmin.vs daysforsolution-based SAMS

8

IdealizedQCMsignatureduringSAMS/ALD

In-situthicknessduringALDoxidesonthiol SAM

1.Avila,J.R.etal.AcsApplMaterInter140721160005002 (2014).

SelectiveAreaALD

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Bae,C.etal.Multisegmentednanotubesbysurface-selectiveatomiclayerdeposition. J.Mater.Chem.C1,621(2012).

K.Nielsch’sgroup,Hamburg U.

Fabricationstepsofmulti-segmentednanotubesusingAAO,SAMS&ALD

ExamplesofTiO2 /ZrO2 segmentednanotubesdeposited inAAOnano-termplate usingOTSSAMS

SAMSinplasmonichotelectronPV

q ExampleofALD/SAMSheterostructure usingSavannah

q SAMSlengthcontrolhotelectroninjection

q Open-circuitvoltagefunctionofSAMSdipole

q ShortcircuitcurrentfunctionofSAMS functionalization

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TiO2 banddiagramandpassivationeffectofSAMS

ImpactofSAMSlengthoninjectionefficiency,photonconversionefficiencyandshortcircuitcurrent

1.PelayoGarcíadeArquer,F.,Nanoscale7,2281–2288 (2015).

HARDWARE

11

SAMSkitspecs

12

Systems SavannahS100,200&300

Max.#kits/tool Upto2

Substratesize Upto300mmforS300

Typicalruntime 5-20min

Dosecontrol ±0.5µmol

PrecursorTemp Upto200˚C

Accumulatortemperature• 100˚Cwithpressuregauge• Upto150˚C(w/ogauge)

Dosepressurerange 0-10TorrwithBaratron

Co-reactant H2O,ozone,air

Seedlayers ALDoxidesandmetals

Pump Adixen2021C2withpurgekit

Softw.Integration,endpointcontrolImplementedinstandardSavannah

software

FDTScontactangle >110 ̊

FOTSangle >105 ̊

DTSangle >100 ̊

In-situdiagnostic

q Spectroscopicellipsometry(WoollamM2000V)

q QuartzCrystalMicrobalanceq Providereal-timesub-Åresolutionand

quickacquisitionrateq Idealforthicknessmonitoring,rapid

processoptimization,growthcharacterizationwithmulticomponentorheterogeneousfilms

13

80

60

40

20

0

Thic

knes

s [Å

]

300025002000150010005000

Time [s]

SE_thick QCM_2

In-situSEandQCMdataduringAl2O3 run

36

34

32

30

28

26

24

22

20 T

hickn

ess

[Å]

1650160015501500145014001350

Time [s]

Insitu SE Insiu QCM

In-situSEandQCMonSavannahGen2

RESULTSUltratechCNTdata

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85#

90#

95#

100#

105#

110#

0.25s# 1s# 5s#

Contact'a

ngle'[d

egres]'

Pulse'2me'[s]'

60s#

300s#

600s#

Source#@#105°C#Reactor#@#105°C#

Expo#;me#[s]#

WatercontactanglesforDTSonAl2O3 ALDfilmsasafunctionofdose(pulsetime)andexposuretime

DTScoatingonALDalumina

15

q Precursor:Dodecyltricholorosilane(DTS)q Sample:Siliconwith20nmALDAl2O3

q Sampleprep:none

WateronAl2O3 andAl2O3+DTS

Impactofreactantdose

16

108$109$110$111$112$113$114$115$116$

0$ 2$ 4$ 6$ 8$

Contact'a

ngle'[˚]'

SAMS'dose'[Torr]'

FOTS$

FDTS$

DTSonSiO2Impactofseedlayer

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SiO2 SiO2+DTS

SiO2 +1cyALD+DTS

SiO2 +4cyALD+DTS

SiO2 +10cyALD+DTS

Significant increaseofwatercontactangleusingALDseedlayerfollowedbyDTS

q Sample10kÅthermalSiO2

q Deposit1-10cyclesofALDasaseedlayerq VaporphaseSAMSdepositionfor10min.

In-situQCMcharacterizationduringFDTSgrowth

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9

8

7

6

5

4

3

2

1

0

Insit

u F

DTS

Thic

knes

s [Å

]

1086420

Expo Time [min]

ExSitu Contact Angle Bare Si + nat.ox. 94˚ x1 pre-expo H2O pulse 98˚ x1 pre-expo TMA pulse 113˚ x1 pre-expo TMA/H2O cycle 114˚

InsituQCM

thickness[Å]

Insitu seed1Insitu seed2

In-situQCMcharacterizationduringALDonSAMS

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Summary

q ALDandSAMsprovideaversatilesetofsolutionstocoat&functionalizesurfaceswithorganicandinorganicfilms

q Vapor-phasedepositionofSAMScanbeachievedinminutesandprovidesoptimalcoverageinhighaspectratio3Dnanostructures

q In-situsensing(QCM,SE)provideuniqueopportunitiestooptimizebothALDandSAMsprocesses

q VaporphaseSAMSrecipesdevelopedinS200

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