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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#[email protected]
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
Am
t
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