Karl Suss MA6 User manual

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

NANOSYSTEM FABRICATION FACILITY (NFF), HKUST
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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!"