Edwards AUTO 306 User manual

EO86-67-880
Issue A
Description Item Number
Water Cooled Crystal Holder
Oscillator Unit
Crystals (pack of 5)
EO86-67-000
EO86-66-000
EO86-68-000
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.
Edwards High Vacuum International
Manor Royal, Crawley, West Sussex, RH10 2LW, UK
Telephone: [phone] Fax: [phone] Telex: 87123 Edivac G

CONTENTS
Section Title Page
1
1.1
1.2
1.3
1.3.1
1.3.2
1.3.3
1
1
1
2
2
2
4
INTRODUCTION
Scopeof this manual
Definition of terms
Generaldescription
Water CooledCrystal Holder
Oscillator Unit
Crystals
2
2.1
2.2.1
2.2.2
2.2.3
2.2
2.3
5
5
5
5
5
5
5
TECHNICAL DATA
Water Cooled Crystal Holder
Performance
Mechanicaldata
Materials
Oscillator Unit
Crystals
3
3.1
3.2
3.3
3.4
3.4.1
3.4.2
3.5
3.6
7
7
8
8
9
10
13
13
13
INSTALLA TION
Unpack and inspect
Safety
Generalinstallation requirements
How to install the Water Cooled Crystal Holder
Install into an AUTO 306
Install into other coatingunits
How to install the Oscillator Unit
How to prepare and install acrystal into thecrystal head
4
4.1
4.2
4.3
4.4
4.4
15
15
15
15
16
16
MAINTENANCE
Safetyinfonnation
Removalof deposits from tl\e crystal
Crystal electricalcontacts
Crystal check
Routine maintenance
5
5.1
5.2
STORAGE AND DISPOSAL
Storage
Disposal
17
17
17
6
6.1
6.2
SPARES AND ACCESSORIES
Introduction
Spares
18
18
18
RETURN OF EDW ARDS EQUIPMENT
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8
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Water Cooled Crystal Holder i

Illustrations
Figure Title Page
1
2
3
4
5
6
1
3
6
11
12
12
Definition of processtenns
Application of theWater Cooled Crystal Holder
Dimensions
Component parts of theWater CooledCrystal Holder
Cooling-water connections
Quick-fit water connectors
Associated publications
Publication title Publication Number
FTMS Film Thickness Monitor EO86-6S-000
ii Water Cooled Crystal Holder

1INTRODUCTION
1.1 Scope of this manual
Thismanual provides installation, operationandmaintenanceinstructions for theWater Cooled
Crystal Holder, Crystals and Oscillator Unil You must usetheWater Cooled Crystal Holder,
Crystalsand Oscillator Unit asspecifiedin this manual.
Readthis manual before you install and operatetheWater Cooled Crystal Holder, Crystals and
Oscillator Unit. Important safety information is highlighted as WARNING and CAUTION
instructions; you must obey theseinstructions. The use of WARNINGS and CAUTIONS is
defined below.
The units used throughout this manual conform to the SI international system of units of
measurement.
Definition of terms
1.2
Figure 1defines the processterms usedin this instruction manual.
1.
2.
3.
4.
5.
6.
7.
Substrate
Crystal head
Crystal
Deposition {deposition rate)
Deposition source
Evaporation {evaporation rate)
Deposited layer
<
,
...
0;
0
,
a
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Figure 1 -Definition of process terms
Water Cooled Crystal Holder 1

General description
Water Cooled Crystal Holder
TheWater Cooled Crystal Holder is usedin conjunction with acrystal,anOscillator Unit and a
film thicknessmonitor {suchasthe Edwards FrM5) asshown in Figure 2. You canmount the
Water Cooled Crystal Holder in a vacuum chamberof acoatingsystemto monitor the rateand
thicknessof deposition from adeposition source.
The crystal is held in a water cooled crystal headto shield it from radiated heatand to remove
heatgainedfrom thedepositedlayer. Thecrystalisfully shroudedandyou may useit in systems
using thermal, electron beam or sputter deposition techniques without modification. An
aperture in the crystal headdefines theareaof crystal exposedto thedeposited layer.
The cooling-water is delivered to the crystal headby coiled copper tubes. The copper tubes
support thecrystal headandaresemi-flexibletoallow you toposition thecrystalheadin position
for operation. The tubesare long enough to beusedin a largechamberand flexible enough to
bebent into a complete loop in a small chamberif required. Becausethe internal diameter of
the coiled copper tubesis small, they must beconnectedin parallel with themain cooling-water
supply for thecoating system. A filter isincluded in thewater supply tube toprevent thecrystal
head from becoming clogged with water-borne debris.
Water and electrical connections to the vacuum side of the Water Cooled Crystal Holder are
made through a single vacuum leadthrough which will fit a standard Edwards baseplate
leadthrough hole or other baseplateleadthrough holes.
The electrical connection from the Oscillator Unit to the crystal is made through coaxial cable
and a BNC plug. On the vacuum side of the leadthrough, coaxialcableis used to connectthe
leadthrough to the crystal head. Thecrystal hastwo connections,'live' and 'earth'. Thecentre
conductor of the coaxial cableis live and the sheathis earthed. The side of the crystal which
receivesthedeposited is earthed.
Oscillator Unit
The Oscillator Unit is a sealeddevice, used with the Water Cooled Crystal Holder and a film
thickness monitor such as the FrMS. The unit contains an oscillator circuit, the oscillating
frequencyof which iscontrolled by thenatural frequencyof thecrystal. Asdepositedlayerforms
on the crystal, the natural oscillating frequency decreases,togetherwith the output frequency
of the oscillator. The changein frequency is detectedby the thicknessmonitor, which converts
the frequency changeinto deposition rateand thicknessinformation.
2Water Cooled Crystal Holder

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1.
2.
3.
4.
5.
6.
7.
8.
9.
Crystal, mounted in crystal head
Short coaxial cable
Earth connection
Oscillator Unit
Long coaxial cable
Input from crystal sensor 2 (if fitted)
Shutter 2 connection (if fitted)
Remote shutter control connections
Remote shutter control
10. FTM5 or similar film thickness monitor
11. Analogue device (chart recorder)
12. Shutter controller panel
13. Cooling water hoses
14. Source shutter actuator
15. Source shutter
16. Bell jar
17. Water Cooled Crystal Holder
Figure 2- Application of the Water Cooled Crystal Holder
Water Cooled Crystal Holder 3
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1.3.3 Crystals
The sensingelement of the Water Cooled Crystal Holder is a quartz crystal. The crystal is a
plano-convex plate which is excited into thicknessshear-modevibrations by signals from the
Oscillator Unit. When new, the crystal oscillatesat a frequencyof about 6MHz.
Thefrequencyof oscillation is determined by themassof deposited layer on thecrystal surface
when it is exposedto the deposition source. As the depositedlayer builds up, the oscillations
slow down. Edwards useaplano-convex crystalsincethisshapeinducesmost of theoscillations
to occurin the central exposedregion of the crystal. This increasesthe sensitivity of the crystal
to themassof thedeposited layer and meansthat thecrystalmay befirmly clamped around the
rim to improve heat transfer to the Water CooledCrystal Holder
4Water Cooled Crystal Holder

2TECHNICAL DA TA
2.1 Water Cooled Crystal Holder
Perfonnance
0.51.min-l at 10to 25°c
Less than 1 x 10-9mbar.ls-l
0.251.min-l
30°C
6OoC
Cooling-water requirement for substrate
operating temperatures up to 300°c
Maximum leak rate
Minimum cooling-water flow rate
Maximum cooling-water inlet temperature
Maximum cooling-water outlet temperature
2.2.2 Mechanical data
Dimensions
Mass(crystal holder complete)
Baseplateleadthrough hole size
Cooling-water hoseconnectors
SeeFigure 2
1.8kg
25 to 27 mm
Push-in connectors for 8 mm
old nylon tubing or riffled
connectors for 6 mm ild tubing
BNC male, 50,0.
Electrical connection
Materials
Crystal headenclosure
Internal water filter Nickel plated copper alloy
Stainless steel 0.75 mm mesh
2.2 Oscillator Unit
8Sx2Sx2Smm
6MHz
94
Size
Nominal unloaded oscillator frequency
Mass
2.3 Crystals
Crystal size
Crystal operating frequency (unloaded)
Materials
14rnmdiameter,
approximately 0.3 rnm thick
6MHz
Quartz, gold plated electrodes
Water Cooled Crystal Holder 5

15
/M3
1Adjustable to suit chamber size
Figure 3 -Dimensions
6Water Cooled Crystal Holder

3INSTALLATION
3.1 Unpack and inspect
Remove all packing ma terials and protecti vecovers and check the Water Cooled Crystal Holder,
Crystals and Oscillator Unit.
If any of the products is damaged,notify your supplier and the carrier in writing within three
days;statetheItem Number of theproduct togetherwith your order number andyou
invoice number. Retainall packing materialsfor inspection. Do not usethedamaged item.
Checkthat your packagecontainstheitemslisted below. If any of theseitems is missing, notify
your supplier in writing within threedays.
Water Cooled Crystal Holder
Oscillator Unit
Qty Description Check (.I')
1
1a
a
Oscillator Unit
Set of two co-axial cables
Crystals
Qty Description Check (./)
1Pack of 5 crystals 0
If anyitem isnot tobeusedimmediately, replacetheprotective covers. Storetheitem in suitable
conditions, asdescribedin Section5.
Water Cooled Crystal Holder 7

Safety
3.2
Theseaccessorieshave beendesignedfor installation and useon the Edwards AUTO 306
vacuum coaterwith its comprehensivesafetyfeatures. If you install and usethem on any
other equipment, you must takesuitable safetyprecautions to ensurethat you adequately
support, safely enclose, insulate, interlock and provide short circuit protection, as
appropriate.
All installation work must bedoneby asuitably trained and supervised person.
Switchoff theelectrical supply anddisconnectthecoating systemfrom theelectricalsupply
beforeyou start installation work.
Surfacesinside the AUTO 306canbevery hot or very cold. Ensurethat you take adequate
precautions to avoid touching hot or cold surfacessuchasthe pump body, sourceholders,
substratesand components associatedwith Plasmagloand other HT dischargeprocesses.
Full details of theprocedure for opening the AUTO 306cabinetaregiven in theinstruction
manual for the AUTO 306. Follow these instructions carefully to prevent damage to
componentssuchasthe chamberleak valve.
3.3 General installation requirements
Note thepoints listed below when you install theWater Cooled Crystal Holder:
Locatethe crystal head in a definite, reproducible position relative to the sourceand the
substrate,preferably at thesamedistanceasthesubstratefrom thesource.Thedistancethat
you placethecrystal head from thesourceis important; themassof thedeposited layer on
agiven areaof the crystal is inversely proportional to the squareof the distance from the
source.If you increasethedistance,themassof depositedlayer onagiven areaof thecrystal
will decrease.
Mount thecrystal faceat right anglesto theline-of-sight of the source. The effectiveareaof
thecrystalexposedto the sourceisproportional tothecosineof theangleof inddence of the
source.
.AlJowa smalJ amount of adjusb1)ent for the crystal head for when you to set-up the system.
Position the crystal head so that you can remove and insert the crystal
Securelysupport theelectrical cablesand cooling-water hoses.
8Water Cooled Crystal Holder

The coaxial cableon the vacuum side of the leadthrough connectsthe leadthrough to the
crystal head. The cableis insulated with PTFEand you do not needto usemore insulation
unlessyou usetemperaturesabove300°c inside thechamber. For normal work, wrap the
coaxialcableloosely round the coiled copper tubes. If you usetemperaturesabove300°C,
wrap the cableand coiled coppertubeswith aluminium foil to protect them. It is important
that you do this if you useelectronbeamand RFsputtering sources.
.
You must position thecrystal headcarefully in RFsputtering systemsto avoid interference.
You must provide sufficient cooling-water to theWater Cooled Crystal Holder, especially
when you areusing radiant heaters.You may usetheWater CooledCrystal Holder without
cooling-water only for short, low temperature depositions. If you usewater which is too
cold, condensation may form on the crystal and the crystal head when the coating system
is vented to atmospheric pressure. Too much condensationmay causethe crystal to stop
oscillating; this condition is temporary and the crystal will function correctly when the
condensationevaporates.
Usea shutter to shield the crystal head during theinitial soakperiod to protect the crystal
from any spitting that may occur. If a small droplet of molten material hits the crystal
surface,the crystal may be damagedand it may stop oscillating.
3.4 How to install the Water Cooled Crystal Holder
A typical installation of the WaterCooled Crystal Holder is shown in Figure 2. Figure 4 shows
thewater hoseconnectionsfor anAUTa 306.Figure5showshow tousethequick fit connectors.
Beforeyou start theinstallation procedurebelow, selectthebestbaseplateleadthrough hole for
your application. To prevent vibration of the crystal headwhen it is in use,you may want to
attachthe crystal headtoanearbysupport in your chamber;todo this,you must makeabracket
which canbefixed to the two M3 tapped holesin thebackof thecrystal head(refer to Figure 3).
Oneof thecooling-water connectorson thebottom of theleadthrough hasawater filter inserted
into it (refer to Figure 6, item 13):you must identify this connector and ensure that the water
supply hoseis fitted to this connector.
You must cut the nylon tube (supplied with the Water Cooled Crystal Holder) to the correct
length for your installation: thelength of tubethat you will require will dependon the position
of thebaseplateleadthrough hole you have usedfor the Water Cooled Crystal Holder. For the
AUTO 306,themaximum length of tubethat you will require (if you haveusedthehole furthest
from the side panel with the water hoses)will beabout 1.4m. Cut the tube sothat, when it is
installed, there areno loops or bendsin the tube which could restrict the water flow.
Water Cooled Crystal Holder 9

3.4.1 Install into an AUTO 306
In the procedure below I refer to Figures 4 and 5.
1, Switch-off and disconnectthe electrical supply from the AUTO 306 and any accessories
fitted to it.
2. Turn off and drain thecooling-water from the AUTO 306.
3. Remove the nut and washer (Figure 4, item 8 and 9) from the leadthrough of the Water
Cooled Crystal Holder.
4. Check that the 'a ring (Figure4,item 10)is cleanand that it iscorrectly seatedin thegrove
on the leadthrough.
s. Fit the leadthrough in the selectedbaseplateleadthrough hole. Refit the nut and washer
removed previously to secure the leadthrough in place. Tighten the nut to form a
mechanically secureand leak-tight seal.
6. Position the Water CooledCrystalHolder in its operating position; gently bend and expand
the coiled copper tubesif necessary.Do not bend the copper tubescloseto their junction
with the leadthrough asthetubesmay fracture.
7. If you want to attachthecrystalheadto thenearbysupport, screwyour bracket to theback
of the crystal headand fix it to the support
8. Tiethecoaxial cablefrom thecrystalheadto thecoppertubestoensurethat it doesnot touch
other chamber components.
9. Measure the distancefrom thebottom of theleadthrough to thepoint at which you will cut
theAUTO 306water hoses.
10. Cut two water hoses(Figure 5, items 4 and 9) to the required length from the nylon tube
supplied. Cut the endsof thetubeperpendicular to the axisof thetube.
11. Carefully cut into the water supply and return hosesinside theAUTO 306cabinet. Ensure
that you cut theendsof the tubeperpendicular to theaxisof the tube.
12. Fit the 'T' pieces (supplied with the Water Cooled Crystal Holder} to the ends of the
AUTO 306water hoses(Figure5,item 5}.
13. Note which of thecooling-water connectorson thebottom of theleadthrough hasthe water
filter fitted in it (Figure4,item 13). Connectthe two quick-fit couplings (Figure 5, items 3
and 10)to the cooling-water connectorson theundersideof theleadthrough.
14. Insert the prepared water hosesbetween the 'T' piecesand the quick-fit coupling on the
leadthrough. Ensurethat theconnectionsarecorrectly made,with thecooling-water supply
connectedto theconnectorwhich containsthe filter (3).
15. Outside the chamber,connecttheWaterCooledCrystal Holder to theOscillator Unit using
theshorter of thetwo coaxialcablessupplied with theOscillator Unit (refer to Figure 2and
Section3.5).
16. Reconnectthewater supply to theAUTa 306andcheckthattherearenoleaksfrom thenew
connections.
10 Water Cooled Crystal Holder

1.
2.
3.
4.
5.
6.
7.
8.
9.
10. Baseplate '0' ring
11. Glass seal '0' ring
12. Coaxial cable
13. Cooling water connector (with filter)
14. 8 mm equal ended coupling
15. Riffled connector (optional)
16. Cooling water connector
17. Fixing hole for M3 screw
Sprung fingers
Water cooled crystal head
Crystal enclosure
Crystal
Push-on connector
Leadthrough
BNC socket
Vacuum leadthrough nut
Vacuum leadthrough washer
A
B
Front of crystal
Rear of crystal
Figure 4 -Component parts of the Water Cooled Crystal Holder
Water Cooled Crystal Holder 11

Figure 5 -Cooling water connections
AD/O515/A
mt
3
2
1
Push hose into connector
Hose secured in position
Push in collet to release hose
1.
2.
3.
Figure 6- Quick-fit water connectors
Water Cooled Crystal Holder
12

17. If you will fit an Oscillator Unit inside the AUTO 306cabinet, refer to Section 3.5. Otherwise,
re-connect the electrical supply.
Install into other coating units
You should usetheprocedure in Section3.4.1.Note,however,that if your coating unit doesnot
have8 mm external diameter cooling-water hoses,you may haveto usethe riffled connectors
to connectyour water hosesto thebottom of theleadthrough.
3.5 How to install the Oscillator Unit
Connectthe Oscillator Unit between theWater CooledCrystal Holder and your film thickness
monitor (for example,your FTM5) asshown in Figure2.
Ensurethat theOscillator Unit is correctly orientated,with:
the short co-axialcable(2)betweenthecrystal sensor(1)and theOscillator Unit connector
marked XTAL
the long co-axial cable (5) between the film thickness monitor and the Oscillator Unit
connectormarked FTM5.
Support the Oscillator Unit to prevent strain on the electricalconnectors.
How to prepare and install a crystal into the crystal head
Removeand replace the crystal in a clean environment; usean isolated, clean work benchif
possible.To prevent contamination of thecrystal,usecleanlaboratory glovesorplastic tweezers.
Keepnew crystalsin aclosedplastic case.
Youmaypreparethecrystal for useby depositing athin layer(forexarnple, l000A)of aluminium
onit. Install thecrystal into thecrystalheadand follow theinstructions in theinstruction manual
for your film thickness monitor. If you prepare the crystal in this way, it will ensure that the
monitoring systemisfunctioning correctly. It alsocoverstheexposedpart of thecrystal with a
metal which is readily dissolved; this then allows subsequentdeposits to be removed more
easily.
Referto Figure 4. Thecrystal (4)is fitted into thecrystalhead(2). To removethe crystal and fit
anew one,usethe procedure below:
1. Pull the enclosure(3)straight out of thecrystal head(2)by gripping its edgesbetweenyour
thumb and forefinger.
2. Shakeor tap out the usedcrystal.
3. Placeanew crystal (4)in theenclosure(3); checkthat the front of the crystal is facing out of
the aperture (seeFigure 5,insetsA and Bto identify the front and rear of the crystal).
4. Ensurethat the crystal (4)is correctly seatedin thecentreof the enclosure(3).
Water Cooled Crystal Holder 13

5. Push theenclosure(3)gently backinto thecrystal head(2). If theenclosureand crystal are
correctly fitted, the enclosurewill snapinto position to securethe crystal head.
If you havemounted thecrystal headsothat theenclosurefacesupwards (for example,for use
in a sputtering system),you may drop the crystal into thecrystal head (2)with the front of the
crystal facing out of the aperture. Ensurethat the crystal is in the centreof the crystal head (2)
and then carefully push on theenclosure(3).
14 Water Cooled Crystal Holder

4MAINTENANCE
Safety infonnation
Disconnect theelectrical supply from theAUTO 306before you start maintenancework.
Do not touch surfaceswithin theAUTO 306which arevery hot or very cold.
Takesuitable precautions when using solventsand cleaning agents.
4.2 Removal of deposits from the crystal
1. Carefully remove thecrystal from thecrystal headasdescribedin Section3.6.
2. Gently swab the areaof the deposited layer with acotton bud soakedin a suitable solvent.
If thecrystal wasprepared asdescribedin Section3.8,usea5%sodium hydroxide solution
at 20°c to dissolve the aluminium coating on thecrystal.
3. Rinsethoroughly in water and allow to dry.
4. Vapour degreaseor wash the crystal in propanol.
5. Check the crystal and the crystal electricalcontactsfor signsof damage(seeSection4.3); if
they arenot damaged, prepare thecrystal asdescribedin Section3.6.
Crystal electrical contacts
The crystal is electrically connected to the crystal head by two gold crackson the crystal. The
crackon thefront of thecrystal makescontactwith theenclosure(seeFigure 6,item 3).Thetrack
on the rear of the crystal makes contact with the sprung fingers inside the crystal head (see
Figure 4,item 1).
Cleanthe gold tracks on the crystal, the inside of the crystal headand the sprung fingers using
acotton bud soakedin a suitable solvent (suchaspropanol).
Carefully checkthegold tracksand thesprung fingers for signsof damagewhich may result in
inadequate contact for the effective electrical signal transfer from the crystal head to the
Oscillator Unit.
Water Cooled Crystal Holder 15

4.4 Crystal check
If available, use the crystal check facility on your film thickness monitor to detennine the
condition of the crystal {and other parts of thecrystal sensor). Further instructions on how to
checkacrystal arecontained in theinstruction manual for you film thicknessmonitor.
4.5 Routine maintenance
.
Cleantheaperture of the crystal headto prevent thebuild up of deposited layer.
Checkthecondition of thebaseplate'a ring when you fit or move the accessory.
Checkthecondition of thecoaxialcableregularly. Replacethecoaxialcableif it isdamaged.
Checkthe condition of the filter in theleadthrough cooling-water connector and clean it if
necessary.
16 Water Cooled Crystal Holder

5STORAGE AND DISPOSAL
5.1 Storage
1. Return the Water Cooled Crystal Holder, Crystals and Oscillator Unit to their protective
packaging.
2. Storein acooldry place.
5.2 Disposal
Dispose of the Water Cooled Crystal Holder, Oscillator Unit and used crystals safely in
accordancewith local and national safetyand environmental requirements.
Water Cooled Crystal Holder 17