Silicon nanowire mass sensors - Harvey Mudd College · PDF fileB. A. Bryce Brian A. Bryce, Jason J. Gorman, SergiyKrylyuk, and Albert Davydov Silicon nanowire mass sensors

B.A.Bryce

Brian A. Bryce, Jason J. Gorman, Sergiy Krylyuk, and Albert Davydov

Silicon nanowire mass sensors

B.A.Bryce

Outline• Introductiontovapor-liquid-solidnanowiregrowth• Literaturenanomechanical measurementofmass• Ouridea• ExperimentalResults• Questions

B.A.Bryce

In1964,R.S.WagnerandW.C.Ellisfirstobserved thegrowthof siliconcrystalsfromAuparticlesduetothepresenceofasiliconvapor.

Thewiresweresolid, theparticlewasaliquideutecticandtheprecursorwasavaporsotheycalledthemethod:vapor-liquid-solid (VLS)growth.

Itdependsontheeutecticpointofabinaryphasediagram.

VLSgrowthwasoriginallycalledwhiskergrowth inthe1970sfollowingWagnerandEllis’sworkbuteventuallyevolvedinthe1990sintonanowiregrowth,capableofcreatingrodsatnanoscaledimensions.

Vapor-liquid-solidnanowiregrowth

B.A.Bryce

Attogram detectionusingnanoelectromechanicaloscillators

B.Ilic,H.G.Craighead,S.Krylov,W.Senaratne,C.Ober,andP.Neuzil,J.Appl.Phys.95,3694(2004).

𝑓" =𝛽𝑙 &

2𝜋𝑡𝑙&

𝐸12𝜌(1 + 4𝛾)

�

𝛾 =𝑚𝜌𝐴𝑙

Resolvablemass=0.39ag

B.A.Bryce

Nanowirecantileversformassbasedsensing

Idea:Usesitecontrolled growthofSivapor-liquid-solidwirestocreatehighsensitivitymasssensingplatform

𝑓" =𝛽𝑙 &

12𝜋𝑡𝑙&

5𝐸2𝜌

�

𝛽𝑙 ⇒ 𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛𝑡𝑜𝑡𝑟𝑎𝑛𝑠𝑖𝑑𝑒𝑛𝑡𝑖𝑎𝑙

Taperedregularhexagonwithendmass:

B.A.Bryce

Phase1:Sitecontrolledgrowthandsensitivity

Idea Reality

𝑄 > 13000

Estimatedresolvablemass=0.07-0.14ag

𝜎F = 0.5 − 1𝐻𝑧

B.A.Bryce

Questions?

B.A.Bryce

SiliconnanowiremasssensorsBrianA.Bryce,JasonJ.Gorman,SergiyKrylyuk,andAlbertDavydov

20µm

Idea Reality

Betterthan0.14attogramsensitivity

(0.00000000000000000014 g)

B.A.Bryce

Attogram detectionusingnanoelectromechanicaloscillators

B.Ilic,H.G.Craighead,S.Krylov,W.Senaratne,C.Ober,andP.Neuzil,J.Appl.Phys.95,3694(2004).

2µm

𝑓" =𝛽𝑙 &

2𝜋𝑡𝑙&

𝐸12𝜌(1 + 4𝛾)

�

𝛾 =𝑚𝜌𝐴𝑙

𝑄 = 8500

Resolvablemass=0.39ag

B.A.Bryce

Measurementprinciple- Fabry–Pérot interferometer

𝑑LFF

𝑎 = 𝛼N cos 𝜔𝑡

𝑏 = 𝛼&cos(𝜔𝑡 +4𝜋𝑑LFF𝜆 )

Cantilever

Substrate

B.A.Bryce

Nanowirecantileversformassbasedsensing

Idea:Usesitecontrolled growthofSivapor-liquid-solidwirestocreatehighsensitivitymasssensingplatform

Motivation:

• Likelyhigh-Qaswiresaredamagefreeandsinglecrystal

• Auontipcanbefunctionalized andismostsensitivelocationformassloading

• CanbeintegratedwithotherSibasedtechnologytoallowformultiplexing

• Canbescaledtonanoscopic dimensions withoutelectronbeamlithography

• Highly integratedsensor isaninterestingmetrologysystem-on-a-moduleproblem

𝑓" =𝛽𝑙 &

12𝜋𝑡𝑙&

5𝐸2𝜌

�

Goal:OnechipandPCBwithsamemeasurementqualityasentirelabofequipment

𝛽𝑙 ⇒ 𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛𝑡𝑜𝑡𝑟𝑎𝑛𝑠𝑖𝑑𝑒𝑛𝑡𝑖𝑎𝑙

Taperedregularhexagonwithendmass:

B.A.Bryce

Phase1:Showsitecontrolledgrowthonsidewallsofhigh-QVLScantilevers,andestimatemasssensitivity

Phase2:Integratephotodetector, andthermaldrivertoallowforpartialmultiplexing

Phase3:Integratelightsourceforfullmultiplexing

Phase4:Integratevacuumpumptocompletehigh resolutionmassdetectionsystem

B.A.Bryce

Phase1:Showsitecontrolledgrowthonsidewallsofhigh-QVLScantilevers,andestimatemasssensitivity

B.A.Bryce

4µm

1) Growawirewherewewant

2) Growitinaparticulardirection

3) Growone wire

Controlisneeded

B.A.Bryce

Nanowirereactor

SystemFeatures:q 4-zonefurnace;quartzreactorfor2”wafersq Variablepressure(3mTorr – 760Torr)withN2/H2 carriergasq SiH4 andSiCl4 precursorsq Insitu dopingforn- (PH3)and p- (BCl3)types

Exhaust

I II III IVInlet

SiNWsgrowthconditions:

Tgrowth =500-- 1050Cà 900C

P=10-- 760Torrà 600Torr

Growthrate=0.1-- 10um/min

SiH4v Sis400-650C

10-600 torr

SiCl4v Sis900C

B.A.Bryce

Phase1:Sitecontrolledgrowthandsensitivity

Idea Reality

B.A.Bryce

Theinstrument(Phase1)He

NeLaser

Polarizer Polarizer

BS

BS

LED

Köhler

illum

inatior

Objective Dichroicmirror

TubeLens CameraPhotodiode

He/Arinlet

Todrypump

VacuumChamber

OnXYZstage

ToElectronics

B.A.Bryce

Theinstrument(Phase1)

Photodetector TransimpedanceAmplifier

Piezo

NetworkAnalyzer

B.A.Bryce

Phase1:Sitecontrolledgrowthandsensitivity

Idea Reality

𝑄 > 13000

Estimatedresolvablemass=0.07-0.14ag

𝜎F = 0.5 − 1𝐻𝑧

B.A.Bryce

Phase2devicedesign

HeaterPhotodiode

NanowireSensor

Metal1

Metal2

Au

p-Si

n-Si

SiO2

B.A.Bryce

Phase2devicerealityHeaterPhotodiode

NanowireSensor

Metal1

Metal2

Au

p-Si

n-Si

SiO2

10layersoflithography!1. Markdefinition(L+RIE)2. Oxidize(RCA+tube)3. Trenchdefinition(L+RIE+KOH)4. Oxidize(RCA+tube)5. VIAfordiode (L+RIE+HF)6. n+ poly-Sigrowth7. PolySelect1(L+RIE)8. PolySelect2(L+RIE)9. M0Liftoff(L+evaporation)10. PECVDSiO2+SiNx11. VIAthroughSiNx (L+RIE)12. Windowopen(L+HF)13. Audeposition (L+HF+evaporation)14. Wiregrowth15. Contacts(L+HF+evaporation)

20µm

B.A.Bryce

20µm

Useyourtitleslideeffectively:• Coremessage• Getpeopletowanttolisten

B.A.Bryce

Brian A. Bryce, Jason J. Gorman, Sergiy Krylyuk, and Albert Davydov

Silicon nanowire mass sensors

B.A.Bryce

SiliconnanowiremasssensorsBrianA.Bryce,JasonJ.Gorman,SergiyKrylyuk,andAlbertDavydov

20µm

Idea Reality

Betterthan0.14attogramsensitivity

(0.00000000000000000014 g)

B.A.Bryce

20µm

Outlineswastetime*

*Exceptionfortalkslongerthan1hourorsuperformalsettings

B.A.Bryce

Outline• Introductiontovapor-liquid-solidnanowiregrowth• Literaturenanomechanical measurementofmass• Ouridea• ExperimentalResults• Questions

B.A.Bryce

20µm

Keeptexttominimum

Textheavyslidesaregenerallybad

B.A.Bryce

In1964,R.S.WagnerandW.C.Ellisfirstobserved thegrowthof siliconcrystalsfromAuparticlesduetothepresenceofasiliconvapor.

Thewiresweresolid, theparticlewasaliquideutecticandtheprecursorwasavaporsotheycalledthemethod:vapor-liquid-solid (VLS)growth.

Itdependsontheeutecticpointofabinaryphasediagram.

VLSgrowthwasoriginallycalledwhiskergrowth inthe1970sfollowingWagnerandEllis’sworkbuteventuallyevolvedinthe1990sintonanowiregrowth,capableofcreatingrodsatnanoscaledimensions.

Vapor-liquid-solidnanowiregrowth

B.A.Bryce

20µm

LabelthingsclearlyMakefontslargeenoughtoread

B.A.Bryce

Attogram detectionusingnanoelectromechanicaloscillators

B.Ilic,H.G.Craighead,S.Krylov,W.Senaratne,C.Ober,andP.Neuzil,J.Appl.Phys.95,3694(2004).

Resolvablemass=0.39agNoscale

Toosmall

B.A.Bryce

Attogram detectionusingnanoelectromechanicaloscillators

B.Ilic,H.G.Craighead,S.Krylov,W.Senaratne,C.Ober,andP.Neuzil,J.Appl.Phys.95,3694(2004).

2µm

𝑓" =𝛽𝑙 &

2𝜋𝑡𝑙&

𝐸12𝜌(1 + 4𝛾)

�

𝛾 =𝑚𝜌𝐴𝑙

𝑄 = 8500

Resolvablemass=0.39ag

B.A.Bryce

20µm

Clearlyexplainwhyyouhavemadedesignchoices

B.A.Bryce

Nanowirecantileversformassbasedsensing

Idea:Usesitecontrolled growthofSivapor-liquid-solidwirestocreatehighsensitivitymasssensingplatform

𝑓" =𝛽𝑙 &

12𝜋𝑡𝑙&

5𝐸2𝜌

�

𝛽𝑙 ⇒ 𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛𝑡𝑜𝑡𝑟𝑎𝑛𝑠𝑖𝑑𝑒𝑛𝑡𝑖𝑎𝑙

Taperedregularhexagonwithendmass:

B.A.Bryce

Nanowirecantileversformassbasedsensing

Idea:Usesitecontrolled growthofSivapor-liquid-solidwirestocreatehighsensitivitymasssensingplatform

Motivation:

• Likelyhigh-Qaswiresaredamagefreeandsinglecrystal

• Auontipcanbefunctionalized andismostsensitivelocationformassloading

• CanbeintegratedwithotherSibasedtechnologytoallowformultiplexing

• Canbescaledtonanoscopic dimensions withoutelectronbeamlithography

• Highly integratedsensor isaninterestingmetrologysystem-on-a-moduleproblem

𝑓" =𝛽𝑙 &

12𝜋𝑡𝑙&

5𝐸2𝜌

�

Goal:OnechipandPCBwithsamemeasurementqualityasentirelabofequipment

𝛽𝑙 ⇒ 𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛𝑡𝑜𝑡𝑟𝑎𝑛𝑠𝑖𝑑𝑒𝑛𝑡𝑖𝑎𝑙

Taperedregularhexagonwithendmass:

B.A.Bryce

20µm

Endwiththemessageyouwantremembered orsomethingtomake

peopletalktoyouafter

B.A.Bryce

Questions?

B.A.Bryce

Phase2devicerealityHeaterPhotodiode

NanowireSensor

Metal1

Metal2

Au

p-Si

n-Si

SiO2

10layersoflithography!1. Markdefinition(L+RIE)2. Oxidize(RCA+tube)3. Trenchdefinition(L+RIE+KOH)4. Oxidize(RCA+tube)5. VIAfordiode (L+RIE+HF)6. n+ poly-Sigrowth7. PolySelect1(L+RIE)8. PolySelect2(L+RIE)9. M0Liftoff(L+evaporation)10. PECVDSiO2+SiNx11. VIAthroughSiNx (L+RIE)12. Windowopen(L+HF)13. Audeposition (L+HF+evaporation)14. Wiregrowth15. Contacts(L+HF+evaporation)

20µm

B.A.Bryce

20µm

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them,whatdotheyknow,whatdotheynotknow