Karl Suss MA6 User manual

NANOSYSTEM FABRICATION FACILITY (NFF), HKUST
Version 1.1
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Standard Operating Manual
___________________________________________________________
Karl Suss MA6 Mask Aligner

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Contents
1. Picture and Location
2. Process Capabilities
2.1 Cleanliness Standard
2.2 Substrate Size
2.3 Photo Mask Size
2.4 Alignment Accuracy
2.5 Resolution
3. Contact List and How to Become a Qualified User
3.1 Emergency Response and Communications
3.2 Training to Become a Qualified MA6 User
4. Operating Procedures
4.1 System Description
4.2 Safety Warnings
4.3 Operation Precautions and Rules
4.4 Initial Status checks
4.5 Initial System Checks
4.6 Power on Procedure (For Staff ONLY!)
4.7 Modify Parameters
4.8 Mask Loading
4.9 Wafer Loading
4.10 Top Side Alignment
4.11 Wafer Alignment
4.12 Wafer Exposure
4.13 Mask Unloading
4.14 Bottom Side Alignment
4.15 Process Recording during the Process
4.16 Clean up
4.17 Check out
4.18 Machine Shutdown (For Staff ONLY!)

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Karl Suss MA6 Mask Aligner
1. Picture and Location
This tool is located at NFF Room 2240 Cleanroom Class 100.
2. Process Capabilities
2.1 Cleanliness Standard:
Suss MA6#1 Mask Aligner is classified as a “Non-Standard” equipment;
Suss MA6#2 Mask Aligner is classified as a “Clean/Semi-Clean”.
2.2 Substrate Size: TSA is >5mm2to 2”, or 4”; BSA is 2” or 4”
2.3 Photo mask Size: 5” Square
2.4 Alignment Accuracy: TSA (down to 0.5um), BSA (down to 1um)
2.5 Resolution: 1um

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3. Contact List and How to Become a Qualified User
3.1 Emergency Response and Communications
1. Security Control Center: 2358-8999 (24hr) & 2358-6565 (24hr)
2. Safety Officer: Mr. Wing Leong CHUNG 2358-7211 & 64406238
3. Deputy Safety Officer: Mr. Man Wai LEE 2358-7900 & 9621-7708
4. NFF Senior Technician: Mr. Henry YEUNG 2358-7896
5. NFF Technician: Mr. Charles TANG 23587896
3.2 Training to Become a Qualified MA6 User
Please follow the procedure below to become a qualified user.
1. Read through the on-line equipment operating manual of the equipment;
http://www.nff.ust.hk/equipment-and-process/equipment-operation-manual.ht
ml
2. Attend the equipment hand-on operation training either by peer or NFF staff.
3. If training is provided by NFF staff, user must log in NFF equipment
reservation system, and register these trainings.
4. Pass the examination for the equipment operation and the safety.

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4. Operating Procedures
4.1 System Description
1. The Karl Suss MA6 is a top and bottom side mask aligner used for fine lithography
down to 1 micron or below.
2. 350 W mercury arc lamp i-line (365nm) with "smart power supply" is capable of
operating in constant power mode, or constant intensity mode. The default is
constant intensity mode. In this mode, the lamp deteriorates; the power is
automatically adjusted to keep the intensity of the wavelength. Also the Intensity
of the lamp may be read from the power supply during exposure or during a lamp
test.
3. Top side wafer alignment using a conventional microscope, wafer and mask stage
Microscope
Monitor
Brightness,
focus, pressure
controls
Alignment
and exposure
controls
Lamp Power
Supply
controller
Microscope
Wafer Chuck
NIL pressure
controller
Stage X, Y,
rotation
knobs
BSA image
system

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assemblies. Bottom side alignment using bottom viewing optics, CCD imaging
with image frame grabber and LCD display. This allows registration of features on
the backside of a wafer to the topside of the same wafer.
4. Automatic computer control with LCD status for User prompting and keypad entry.
Up to 50 programs may be stored.
5. 5 contact modes may be used for exposure. These include: soft contact, hard
contact, vacuum contact, low vacuum contact, and proximity. Each mode is
easily selected by keypad and may have certain parameters changed by the user.
6. Exposure Modes
Proximity: This is the most careful exposure for the mask. Mask damage is reduced
to a minimum. But the structural resolution is not as high as with any contact
exposure. Between mask and wafer is a distance left (exposure gap).
Soft contact: Mask and wafer are brought in contact. The structural resolution is
better than in proximity exposure. The vacuum securing the wafer onto the chuck is
maintained during exposure. The only force to press the wafer against the mask is the
force applied during WEC.
Hard contact: This is similar to soft contact mode. After the wafer has moved into
contact the vacuum underneath the wafer is switched off and nitrogen is purged under
the wafer instead. So a closer contact between wafer and mask is guaranteed.
Vacuum contact: This mode performs the highest resolution levels. After the WEC
and alignment the wafer is brought into contact with the mask. The rubber seal of a
necessary vacuum chuck is creating a mini chamber between mask and wafer. The
rubber seal pressure is adjustable by the VACUUM SEAL regulator.
Low vacuum contact: This mode is similar to vacuum contact with one difference:
The vacuum level in the wafer chamber can be adjusted by the “LOW VACUUM
ADJUSTMENT” regulator. So the high resolution level of the vacuum contact
exposure can be combined with a minimum mechanical stress for wafer and mask. Set
an appropriate vacuum with the vacuum chamber regulator and test the result using
the “ALIGNMENT CHECK”key.

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Flood Exposure: It is possible to exposure the whole wafer without a mask. After
this mode is selected, the exposure can be started from the initial state by pressing the
“EXPOSURE”key. The exposure takes place as long as the exposure time was set
independent if a mask (and mask holder) is loaded or not.
4.2 Safety Warnings
1. Follow NFF General Lab Safety policy.
2. Do not attempt to run the machine unless you are entitled to do so!
3. Do not open the electronics cabinets and any cover.
4. Do not touch the lamp house. It may burn your skins.
5. Do not attempt to ignite the lamp prior to the completion of 45 minute cool
down. This might cause lamp to explode.
6. Leave nitrogen on for 30 minutes, and then turn it off (if need)!
7. Adjust the COARSE FOCUS TSA only in microscope down position! You
can move the objectives to low and they can crash into the mask, the mask
holder, etc.
8. To prevent mask damage, unload the mask before powering off the machine!
9. The high UV light energy produced by the exposure lamp can cause eye
damage and skin burns. Don’t stare at the light during exposing!
10. If the machine failure while being used, never try to fix the problem by
yourself. Please contact NFF staffs.
11. High power UV lamp is used in this machine. It is mercury-based. It pose a
chemical risk. If a UV lamp break or explode, do not attempt to clean up. You
should isolate the NFF cleanroom and call NFF staffs.
12. The Emergency Off –Button (EMO) red button located in the left on the front

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of the machine. Only use the EMO in emergency situations. Emergency
situations are where injury of personnel or serious damages of the system
impends immediately.
13. In case of fire, keep calm, sound the alarm. If the machine hasn’t shut down,
press EMO Button to shut down the machine and notice NFF staff and UST
security.
14. After exposure to mercury vapors consult doctor immediately!
15. In case of air pressure failure the damping elements are deflated and your
fingers could be jammed.
4.3 Operation Precautions and Rules
1. Please reserve the time slot on your own, and make sure you use your own
time slot to do the exposure process.
2. Please check the checklist and fill all the details of the logbook attached.
3. Change your gloves before operation if your gloves contaminate with any
resist.
4. Do not operate the machine unless you are properly trained and approved by
NFF staff.
5. If mask and wafer are in contact (CONTACT INDICATOR on), don't move
the wafer!
6. Watch out for the microscope movement!
7. No solvents are allowed near the machine!
8. The clip may not be strong enough to hold the mask in place when the mask
holder is inverted. The vacuum should always be ON before the mask holder
is inverted; otherwise the mask will drop and possibly break.
9. Remember to invert the pattern 180 Degrees for BSA masks.
10. Nitrogen failure for longer than 5 minutes will turn off the exposure lamp!
4.4 Initial Status Checks
1. Please check the status of shutdown notice posted in the NFF reservation
website
2. Please check the reservation status on the website, and reserve the right time

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slot by your own.
3. Please check-in the equipment on your own according to the reserved time slot.
If you haven’t check-in, “Loss of wafer vacuum! Confirm with ENTER” error
message will be displayed during process.
4. Before operate the machine, please make sure you have read and check the
check list, and fill the log sheet.
4.5 Initial System Checks
Before starting, verify the machine is in the correct idle state:
1. If system power is off (LCD display and all control LED off), please contact
NFF staff to power on the machine.
2. Mask and wafer trays are on the stage with NO mask or wafer.
3. Pressure = 5-6 bar; Nitrogen = 1-2 bar, Vacuum < -0.8 bar.
4. Check log book that last user had no problem.
5. Move wafer stage to center position (x-axis and y-axis is at 10mm, rotation
knob is at 0).
4.6 Power on Procedure (For Staff ONLY!)
If lamp power is off (no LED readout), turn lamp power on at the power supply under
the table.
Note: System power must be OFF to start the lamp.
1. Ignition of the exposure lamp (CIC 1200)
-Switch “ON”button to power on the Constant Intensity Controller (CIC).
-The software version is shown on the display.
-The CIC performs a self calibration test and displays “ready”.
-Press CP (constant power) key. Display shows “wait”, followed by “Start”.

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-Press “START”key. This will ignite the exposure lamp. LED LAMP
LIFE/POWER is flashing until lamp warming up is finished.
2. Powering on the electronic
-Wait for around 10 minutes let the lamp stable.
-Turn the POWER SWITCH ELECTRONIC on the upper panel control clockwise
into ON position and release.
Machine initialize. The display message is:
-Press the flashing LOAD key on the keyboard when you are asking to do so.
-Now you are asked for:
-Press the flashing ENTER key on the keyboard when you are ask to do so
-"ready for Load"
-The software is loaded and the machine is in initial state, ready for operation:
-All motorized manipulators (TSA, BSA and alignment stage) are set to the
position used before the machine was powered off.
-Press “BSA Microscope” button to deselect BSA Microscope.
4.7 Modify Parameters
1. Select Process: “EDIT PARAMETER” key
Press “EDIT PARAMETER” key to toggle with the “X-Arrow” key to PROCESS,
select with the “Lithography” by the “Y-ARROW” key.
"Watch out machine is starting!"

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2. Select exposure mode: “EDIT PARAMETER” key
Press “EDIT PARAMETER” key to toggle with the “X-Arrow” key to expose
mode, select with the “Vacuum, Low Vacuum, Hard, Soft, Proximity or Flood-E” by
the “Y-ARROW” key.
3. Edit parameters: “EDIT PARAMETER” key
Press “EDIT PARAMETER” key to edit the parameter.
Change all necessary values and confirm by pressing “EDIT PARAMETER” key
again.
Note: 365nm lamp is calibrated to certain intensity; the setting value is shown in front
of the machine.
4. Save all setting: “EDIT PROGRAM” key
This function is an optional possibility to save this parameter set for the future.
Toggle with the “X-ARROW”keys to “SAVE Pgm.”. Select with the “Y-ARROW”
keys a program number. Prior saved programs to the same number will be overwritten
without warning. Save the settings by the “EDIT PROGRAM” key. Existing
programs can be loaded from here.
4.8 Mask Loading
There are two mask holder; one for vacuum or contact mode, and the other one for
proximity.
For Vacuum and contact mode
For Proximity mode

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1. If MA6 is not already in the “CHANGE MASK” mode. “CHANGE MASK”
and “ENTER” keys do not flash. Press ““CHANGE MASK” key.
2. Take out the mask holder, flip it 180and put it on the left compartment. If a mask
is loaded, verify on LCD display that vacuum is still on before pulling out tray. If
not, press “ENTER” key to turn mask vacuum on. Press “ENTER” key to toggle
the mask vacuum off, retract the mechanical mask clamp and remove the mask
after put it on the left compartment.
3. If need a different mask holder, disconnect vacuum hose at machine by pushing in
on red knurled knob and gently pull on the hose. Store unwanted mask holder at
Mask holder Storage area and choose the appropriate mask holder. Place the new
mask holder upside down on the left compartment. Reconnect vacuum hose by
pressing connector firmly into red knob’s opening.
4. Put the mask, chrome side up onto the mask holder against the 3 alignment pins.
The machine instructs: “Change mask – Press ENTER to toggle mask vacuum is:
OFF”.
BSA MICROSCOPE KEY
CHANGE MASK KEY
LOAD
KEY
LAMP TEST KEY
X, Y-ARROW KEYS
FAST KEY
SEP KEYs
ALIGN CONTR/EXP KEY
KEYs
EXPOSURE KEY
UNLOAD KEY
TOP/BOTTOM KEY
ALIGNMENT CHECK KEY
SELECT PROGRAM KEY
EDIT PARAMETER KEY
EDIT PROGRAM KEY
SCAN KEY
LEFT KEY
ENTER KEY
SET REFERENCE KEY
BOTH KEY
RIGHT KEY
GRAB IMAGE KEY
KEY

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5. Toggle the mask vacuum on by press flashing “ENTER”key. Activate the
mechanical mask clamp by pressing the leaf spring down. Verify vacuum is on
before turning mask plate over. (Use hand should unable to move the mask).
6. Flip the mask holder 180 º that your mask is on the bottom and slide mask holder
back into the guides of the machine. Put your hand under the mask holder to avoid
the drop down of the mask.
7. Lock the mask holder slide by press “CHANGE MASK”key again. “Ready for
Load” message appears on the LCD display.
CAUTION: The clip may not be strong enough to hold the mask in place when the
Alignment Pins
Leaf spring

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mask holder is inverted. The vacuum should always be ON before the mask holder is
inverted; otherwise the mask will drop and possibly break.
4.9 Wafer Loading
There are two wafer chucks, one for 4 inch substrates and the other one for pieces
(1.5cm to 2 inch). CAUTION: Do not drop, scratch or otherwise damage the chuck.
Store an unused chuck at its proper location.
1. Choose the expose mode at first, please follow step 4.7.
2. If the chuck is not centered, rotate the chuck to align with chuck holder, and then
move it with micrometer screws to the middle position (x-axis to 10mm, y-axis to
10mm) and adjust the stage rotation knob to 0 (“+”).
3. Press “LOAD” key, pull out the transport slide completely. The machine instructs:
"pull slide and load substrate onto chuck". (“ENTER” and “UNLOAD” key
flashing.)
For substrate size 2”
For 4” substrate size
Adjust vacuum area
Align with Chuck holder

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4. Verify the chuck and check red vacuum seal are clean from stains or particles. Use
Nitrogen blow gun to remove particles or IPA (Isopropyl Alcohol) with a clean
wiper to remove stains if needed.
5. Change the chuck if needed, gently lift the chuck from the bottom side of the slide
and remove. Place proper chuck into circular opening within the slide (Seal faces
up). Align white line on chuck to steel pin on tray. Always handle wafer chuck by
the metal rim, DO NOT touch the center of the chuck directly.
6. Place the substrate on the center of the chuck with the major flat facing you, make
sure all open vacuum holes are covered and the wafer against the three
pre-alignment pins.
7. Press “ENTER” key to turn on the vacuum.
8. The machine instructs: “move slide into machine and confirm with Enter”. Slowly
move the transport slide into the machine.
9. Press “ENTER” key again to confirm. WEC starts automatically. The machine
instructs: “Performing WEC, please wait…” The wafer is adjusted parallel to the
mask and moves to the setting alignment gap. The microscope moves down to
Pre-alignment
pins

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start the alignment (if it is not already down).
10. The machine instructs: “Align Substrate”.
4.10 Top Side Alignment (TSA)
The wafer is aligned to the mask using the topside alignment microscope (TSA). If
the microscope is not lowered automatically press “F1” key, confirm with “ENTER”
key.
TSA SPLITFIELD switch
TSA Z-Movement
Knob
TSA Q-Movement
TSA Beam Splitter
Turret Left
Objective X-Separation
Right
Aperture TSA Illumination Right

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1. The objectives position over the mask using the “X-Y” arrow keys. The fast
speed movement of the microscope may be obtained by pressing “Fast” Key
LED on.
2. An actual TSA-microscope image on the monitor is enabled by turning the
“SPLITFIELD”switch to LEFT. Deactivate “BSA Microscope” key LED off.
This key also switches the controlled manipulator motors from BSA to TSA.
3. This slide on right side of the microscope tube guides the beam to the eyepieces,
the monitor or both.
4. Turn “ILLUMINATION”switch to TSA and select the light intensity with the
potentiometer underneath this switch. Separate intensity selection for the
left/right objective is possible with the aperture located at the left/right
microscope front.
5. Coarse focus is possible by using the “TSA Z-MOVEMENT” knob placed
behind the TSA-microscope. This is used to bring the objective’s depth of focus
into the fine focus range. The fine focus knobs labeled “TOP SUBSTRATE”
should be used to focus on the mask. The fine focus knobs labeled “BOTTOM
SUBSTRATE”should be used to focus on the substrate. Make sure the
“TOP/BOTTOM”key LED is on and adjust the fine focus separately using the
“TOP SUBSTRATE LEFT/RIGHT”regulators. When the “TOP/BOTTOM”
key LED is off, focus control is assigned to the Bottom Substrate knobs.
POWER SWITCH ELECTRONIC
LCD display
VACUUM gauge
VACUUM CHAMBER
gauge (with regulator)
SPLITFIELD switch
CONTACT indicator
ILLUMINATION switch
TOP SUBSTRATE
LEFT/RIGHT focus
WEC PRESSURE
gauge (with regulator)
VACUUM SEAL gauge
(with regulator)
TSA microscope
illumination
BSA/IR microscope
illumination
MAGNIFICATION
BSA switch
BOTTOM SUBSTRATE
LEFT/RIGHT focus BSA
switch
COMPRESSED
AIR gauge
NITROGEN
gauge

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6. Coarse focus is possible by using the “TSA Z-MOVEMENT”knob placed
behind the TSA-microscope. This is used to bring the objective’s depth of focus
into the fine focus range. The fine focus knobs labeled “TOP SUBSTRATE”
should be used to focus on the mask. The fine focus knobs labeled “BOTTOM
SUBSTRATE”should be used to focus on the substrate. Make sure the
“TOP/BOTTOM” key LED is on and adjust the fine focus separately using the
“TOP SUBSTRATE LEFT/RIGHT”regulators. When the “TOP/BOTTOM”
key LED is off, focus control is assigned to the Bottom Substrate knobs.
7. The right/left objective can be moved independently in x-direction to right/left
mask alignment marks using the Objective X-Separation knobs located in the
right/left side of the TSA microscope body. To rotates the microscopes around
the z-axis by turning the knob located in the upper right TSA microscope front
(TSA-Q-MOVEMENT).
8. The MA6 has the ability to remember microscope position via the “Set
reference” key. Simply use x-y arrow keys (fast mode may be used if desired) to
position microscope. Press “SET REFERENCE” key LED comes on.
Reposition microscope with arrow keys to 2nd position, Now Press “SCAN” Key.
Microscope moves back to previous reference position. Press “SCAN” again and
microscope moves back to 2nd position. This method offers easy alignment of
small pieces using a single objective or even a single field TSA micro-scope.
This feature may be used for bottom side microscope also.

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4.11 Wafer Alignment
There are 3 adjustment knobs located near the bottom of the stage to move wafer
relative to the mask, X, Y and R (rotation).
CAUTION: If mask and wafer are in contact mode (Contact indicator on), don’t align
the wafer.
1. With MA6 in alignment mode, and view in split field mode (if wafers already
have a pattern), straighten wafer by turning rotation R knob.
2. Rotate X and Y alignment knobs to align substrate alignment mark central
symmetrical to the mask alignment mark.
3. If too much resistance is felt during wafer movement, or alignment gap needs to
be changed, press “SEP ^”key to decrease separation (z value on display
become less negative) or “SEP v”key to increase separation (z value becomes
more negative.
4. When properly aligned, pressing “ALIGNMENT CHECK” key LED on to
bring the substrate into contact mode. If wafer has patterned, alignment shift due
to contact may be observed through microscope. If unacceptable shift is
observed, substrate or mask may need to be re-cleaned.
Note: The “ALIGNMENT CHECK” key is not available for proximity or soft
Emergency Off Button
Transport Slide
STG-X-Movement Micrometer Screw
STG-Y-Movement Micrometer Screw
STG-Q-Movement Micrometer Screw
Main Power switch
Wafer Chuck

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contact modes. Use the “Alignment/Cont” key instead.
5. Press “ALIGNMENT CHECK” key again to exit this mode, and if alignment is
acceptable, proceed to expose wafer section.
4.12 Wafer Exposure
Lamp power supply should be in CH1 (Constant Intensity @365nm) mode. The
current system intensity setting value is shown in front of the machine. Check process
information or expose test wafer to determine proper exposure time for your needs.
1. If exposure time, as displayed needs to be changed, press “EDIT
PARAMETER”key. Toggle with “X-ARROW”key to EXP. TIME, and use
“Y-ARROW” keys to change exposure time and then press the “EDIT
PARAMETER” key again. The LCD readout should reflect the changed
exposure time.
2. Press “EXPOSURE” key, Watch out as Top Side alignment Microscope move
up and exposure assembly slide out to expose wafer. (Despite the exposure was
initiated pressing the “UNLOAD” key before the light shutter has opened will
continue its exposure program sequence without wafer exposure).
3. Verify exposure power (270-400W) during exposure on lamp readout.
4. After exposure, microscope drops down and wafer chuck moves down to unload
the exposed wafer.
5. The machine instructs: “Pull Slide and unload exposed substrate”. Load another
substrate if desired. Otherwise, move the transport slide back into the machine.
6. Press flashing “ENTER” key followed by “LOAD” key and “ENTER” key
again.
7. Repeat wafer alignment and exposure procedure as describe above.
Note: You should develop and inspect the first wafer before you expose the second
wafer, you might need to adjust the exposure time.