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Abstract The Micro

wavelength mparticles, curreslab-symmetriusing existingseveral possibexperimental o

Laser driveninvestigation theoretical anaA simplified mtested [4]; howconcept all-diehave been lachigh-power lbuilding actuamaking tests oThe all-dielectin previous wReflectors (DBouter surface.cleanroom usideposition tecfabrication tecthe device perdeposition medifferent mateThis work prebuilding an different thintechniques, esfor the acceler

EXPThe fabrica

UCLA’s nanowavelength chwe require maddition, goomechanical strdesirable. We the high indematerial, withstructure presesimplify the eare carried out ____________________________

*Work supported HDTRA1-09-1-00#jyzhou36@ucla.e

BRICATI

J. Zhou#, J. MR

o-Accelerator microstructure ently under dec structure and

g nanofabricatble fabricationoutcomes for m

INTRODn dielectric aat UCLA sin

alysis and simumetallic test swever, results electric devicecking. Recentlasers and pral structures a

on them has bectric accelerator

work [3], and cBR), and peri. Such a deving various nachniques. It ischniques can hrformance. Forthods and pro

erial refractiveesents the firstall-dielectric

n film deposstablishing a teator structure.

PERIMENTtion of the deofabrication f

hosen based onmaterial opticalod thermal rength and higchoose sapph

ex material, ah numerical ented elsewherxperimental opt on Si substra________________

by U.S. Defense T043. edu

ION OF APAR

McNeur, J. B. RR. B. Yoder, M

Platform isfor laser a

evelopment at d can be constrtion technique

n techniques amanufacturing t

DUCTION ccelerators ha

nce 1995[1], ulation results rstructure has bon fabrication

e, and tests of ly, with the drogress in nat the wavelencome possible.r structure has consists of Disiodic diffractivvice can be fanolithographys worth to mehave an imporr example, diffcess parameter index, film ut experimental

accelerator, sition and nentative manu

TAL RESUevice is being facility. Sincen an available l transparencyconductivity

gh breakdown hire as the suband SiO2 as simulation re

re at this confeptimization pro

ate instead of sThreat Reduction A

A LASER-BRTICLE A

Rosenzweig, GManhattanville

s an opticalacceleration o

UCLA. It is ructed in layer

es. We presenand preliminarythis structure.

ave been undewith extensivreported [2] [3]been made ann of a proof-of

such a devicedevelopment onanotechnologyngth scale an been describe

stributed Bragve slots on thfabricated in y and thin filmention that thrtant impact onfferent thin filmrs can result inuniformity, etc results towarby comparin

nanolithographfacture proces

ULTS carried out in

e the resonanlaser is 800nm

y at 800nm. Inand stabilitylimits are als

bstrate, ZrO2 athe low inde

esults for thiference [5]. Tocess, test runsapphire, takinAgency, Grant no.

BASED MACCELERG. Travish, UCL

College, Purch

l-of a

rs nt y

er ve ]. d f-e, of y, d

d g

he a

m he n

m n c. rd g y

ss

n nt m,

n y, o

as x is o

ns g

advantageDBR andruns.

DistribuThe DB

contrast inthem havewell as hmaking thSuch thindepositioncan contratomic sclevel, it imaterials.more elevfast technwhen it codeviatesSputteringof the tarreasonabltechnique

The dDiscoverysource. Tdetermininmaterial, wbut largershows Zrwhere theshowing afew microfilm obtaifilm withindex of 2.17 at 80

Figure 1:by sputtersubstrate;

(a)

MICROSTRATION*

LA, Los Angelhase, NY 1057

e of the waferd the slots are

uted Bragg RBR is made fron refractive inde excellent thehigh laser indhem ideal forn films can bn (ALD), sputrol the film tale, and has his a good can Its main limi

vated cost. Evanique used foomes to compfrom the ideg, on the otherrget as well ae speed. In

e for all the thindepositions ary 550 sputter

The RF power ng the deposiwith high powr gain size anrO2 thin film de thin film haa dome structuons to hundredined with 200W

h grain size tethe thin film,

00nm.

SEM microgrring. (a) RF =(b) RF = 200W

TRUCTUR

les, CA 90095 7 USA

r-scale procesfabricated sep

Reflector om dielectric tdices, e.g. ZrOrmal and mech

duced damager high power be deposited ttering, or evathickness and igh film densit

ndidate for det lies in its lonaporation is a rr thin film deounds, the filmal due to tarr hand, maintas producing gthis work we

n film depositiore conductedring system u

level plays aition rate and

wer having a fand less film undeposited with

as poor adhesiure with diamds of microns. W RF power,

ens of nanomeas measured

raphs of ZrO2 =300W, thin fW, uniform thin

(b)

RE FOR

USA

sing. The dielparately for th

thin films withO2 and SiO2. Bhanical properte threshold (L

laser DBRs [using atomic aporation. As

uniformity oty and low imp

epositing high-ng process timrelatively cheaeposition; how

m compositionrget decomposains the compogood film quale use a sputons.

d with a Dusing a RF pan important ro

film quality oaster depositionniformity. Figh 300W RF pon to the subeter ranging frFig. 1(b) showshowing a un

eters. The refrby ellipsomet

thin film depfilm detachingn film obtained

lectric he test

h high oth of ties as

LIDT), [6][7].

layer ALD

on the purity -index

me and ap and wever, n often sition.

osition lity at ttering

Denton power ole in of the n rate,

g. 1(a) power, strate,

from a ws the niform ractive try, is

osited from d.

Proceedings of IPAC’10, Kyoto, Japan THPD045

03 Linear Colliders, Lepton Accelerators and New Acceleration Techniques

A13 New Acceleration Techniques 4381

w

h

F

F

r

p

H

p

p

h

bpp

SiO2 thin fsystem with Rwith homogengrain size ofhomogeneous index of the fFig. 2. At the 1.455.

Figure 2: Hosputtering at Rright graph is r

Coupling SloTheoretical

periodicity ha800nm, and nsize to range electron beam(FIB) milling Here we report

Electron BeaWe use a

operates at 10pattern in Subsequent todielectric layerpattern in PMM

Figure 3: SEM

After PMMdeposited by sacetone. Mosthowever, at thas shown in Fiat the surrounbreaks off frompiece, instead possibly causeslots, which adheres to th

film is deposiRF power of 40neous grain sizf the SiO2 compared to t

film measured wavelength of

omogeneous SRF = 400W. Lerefractive index

ots study has sh

as to be equalumerical simufrom 100nm t

m lithography (are options to t results of theam Lithograph

Vistec EBP00kV, with 5nA

poly(methyl o the EBL, ther using a lift-oMA with slot w

M images of na

MA patterningsputtering, follt of the thin fihe nano-slots aig. 4. The diele

nding areas, bum the surroundof individual led by depositforms a con

he substrate. S

ited by the s0W. The film ze, as shown film is smalthe ZrO2 film.by ellipsomet

f interest, 800n

SiO2 thin filmeft image is SEx measured by

hown that thel to the laser ulation has optto 300nm. At t(EBL) and focproduce the d

se two approachy G 5000+ES A beam curre

methacrylate pattern is traff technique. F

width 200nm.

ano-slots patter

g, a dielectriclowed by a 10ilm is successarea, lift-off is ectric thin filmut at the slotsdings, and remlines only in thtion on the sintinuous layerSolutions to

ame sputterinis very uniformin Fig. 2. Th

ller and mor. The refractivtry is shown innm, the index i

m deposited byEM micrography ellipsometry.

e coupling slowavelength o

timized the slothis scale, both

cused ion beamdesired patternsches.

system whicent to make thte) (PMMA)ansferred intoFig. 3 shows th

rned in PMMA

c thin film i0-min lift-off infully lifted offnot successful

m is stripped ofs, the thin filmains as a wholhe slots. This iidewalls of thr and stronglavoid sidewal

g m he re ve n is

y h,

ot of ot h

m s.

h he ). a

he

A

is n

ff, l, ff m le is

he y ll

depositionadopting the sidewa

Figure 4:the sputtestill coverthe end of

FocusedA focus

literally athem. Heron a silicofilm, andmaterial. Blift-off prIt is also number potential cleaner poverall de

A FEI N30kV is uselected tresolutionprocess tithe patterwidth of alines havdefined lin

Figure 5:line width

To examdeposited 300nm, toa high voland undersection imFig. 6. Th

n include usbilayer lithogralls.

Lift-off probleered SiO2 filmred. Right imaf the slots.

d Ion Beam Msed ion beam any material, re we first depon substrate, and eventually fBy using this p

rocess, which iworth to menof wet procecontamination rocess promis

evice performanNova 600 FIB used for the mto balance be

n. The beam cuime is about 3 rned slots are about 50nm. Ce smaller critne edges.

Slots patterneh of 50nm.

mine the sidewby ion-beam

o conserve the ltage ion beamrlying slot stru

mages of the slhe sidewalls a

sing evaporatraphy to create

em at the nanom is stripped, bage shows the

illing can be used foproducing na

posit the dielend then use FIBfill in the slotprocess we elimis challenging ntion that this essing steps, from liquids a

es higher filmnce. machine with milling. The ietween procesurrent used hemin for 10 linpresented in F

Compared to Eical dimension

d by dry etch

wall profile, aftm evaporation

sidewall profim is used to cutucture to makelots, taken at 5are fairly straig

tion depositioe an undercut

o-slots area. Mbut the slots ae partial stripp

or direct dry eanoscale patterectric thin filmB to etch slots ts with high minate the neeat the nano reprocess reduceand thus re

and containersm quality and

acceleration voion beam currs time and p

ere is 50pA, annes. SEM imagFig. 5, showinEBL results, thns, and have

using FIB, sho

ter FIB millingto a thickne

ile of the slots.t through the Pe an opening. C52º tilt, are shoght, although

on or along

Most of area is ing at

tch of rns in

m SiO2 in the index

ed of a egime. es the

educes s. This better

oltage rent is pattern nd the ges of

ng slot he FIB

better

owing

g, Pt is ess of Then

Pt film Cross-own in at the

THPD045 Proceedings of IPAC’10, Kyoto, Japan

4382

03 Linear Colliders, Lepton Accelerators and New Acceleration Techniques

A13 New Acceleration Techniques

bmtv

F

v

wpb

F

pr

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bottom there imost. The impthe efficient covacuum gap, simulations anFIB machinindevice, the wrvery long writarea, the sampwill cause serproblems for mbuilding simpl

Figure 6: CrosSiO2 on Si sub

Experimentaprototype micrreflector is maand SiO2, andelectron beam Attempts to somade by usinfuture, and FIsmall structurdimension devthe slots with source with the

is a curve, withpact of the curvoupling of the

will need tond experimentng is that foriting area is ating time. In adple stage has torious stitchingmanufacturing,lified proof-of-

ss section imagbstrate. Images

CONCLal efforts havero-accelerator

ade using sputted coupling slo

lithography anolve the lift-of

ng evaporation IB is only suires, not idealvices. Future w

DBR, and ace vacuum gap

h the center bved structure atelectromagnet

o be investigts. A potentialor manufacturiabout 1cm×1cmddition, to covo be moved phg error. Despit, FIB is still a g-concept protot

ges of the FIBtaken at 52º ti

LUSION been made todevice. The diered dielectric ots are fabricand focused ionff problem wit

instead of spitable for buildl for manufawork includes

ccurate alignmof the accelera

eing etched tht the bottom, ontic field into thgated in futurl problem withing the actuam, leading to ver such a larghysically, whicte the potentiagood option fotypes.

B-milled slots inlt.

oward making stributed Bragthin films ZrO

ated using botn beam millingth EBL will bputtering in thding simplifiecturing actual

s integration oment of electronator structure.

he n

he re h al a

ge h al or

n

a g

O2 th g. be he d l-of n

The auResearch Angeles possible.

[1] J. RoLett.

[2] G. TrEPAC

[3] R. B13th 2008

[4] G. Concpp. 50

[5] J. Mc[6] Y.J.

(2008[7] L. Yu

ACKNOWuthors would l

Facility at thfor making

REFosenzweig, A. M74, 2467 (1995ravish, J. B. RC08, pp. 2827–. Yoder, G. TAdvanced A(AIP Conf. PrTravish,et al

cepts Worksho02507. cNeur,et al.,theGuo,et al., O

8). uan,et al., J. Op

WLEDGEMlike to thank the University the fabricatio

FERENCESMurokh, C. Pe5).

Rosenzweig, J. –2829. Travish, J. Xu,Acceleration Croc. 1086), pp. l.,13th Advap, 2008, (AIP

ese proceedingsOptics & Laser

pt. Soc. Am. B

MENT the Nanoelectr

of Californiaon of this d

S ellegrini, Phys

Xu, Proceedin

, J. B. Rosenzoncepts Work496–500.

anced Accele Conf. Proc. 1

s. r Technol. 40

, 24, 538 (2007

ronics a Los device

. Rev.

ngs of

zweig, kshop,

eration 1086),

0, 677

7).

Proceedings of IPAC’10, Kyoto, Japan THPD045

03 Linear Colliders, Lepton Accelerators and New Acceleration Techniques

A13 New Acceleration Techniques 4383