Cambrios Spin-Coating Guidelines 10-09

Cambrios ClearOhm™ Process
Recommendations
For Spin Coating Formulation
ClearOhm™
Handling and Storage
•  What is shipped:
–  ClearOhm™ Ink AQ: this is the metal ink for coating the transparent
conductive coating
•  Storage
–  Store Metal ink solution and dilution fluid at 4 C to 10 C – DO NOT
FREEZE
•  Settling of dispersion when stored is normal
CAMBRIOS CONFIDENTIAL
Overall Coating Process Flow
Refer to slide 5
Prepare Metal Ink
Can use Corona, UV Ozone
or O2 Plasma,
Substrate clean
Can use filter to dispense:
(please refer to
notes on pg. 9)
Dispense metal Ink
Spin coat
Typical condition: 50 C, 90 s
needs optimization
depending on user’s coating
method, substrate etc.
This is time and temperature
product:
Typical 180 C, 90 s
it is possible to lower
temperature and increase
time for example:
120 C, 5 min.
Dry
Softbake
CAMBRIOS CONFIDENTIAL
Metal Ink Coating Guidelines
•  Metal ink is optimized for spin coating
•  Various sheet resistances can be achieved via:
–  Varying spin speed and other spin coating parameters
•  Cambrios data is generated using Headway CB15 spin coater and a
recessed chuck to minimize chuck marks
–  Spin curves are only guidelines and based on user’s spin coater and
other equipment, user may have to optimize coating conditions to
achieve desired sheet resistance
–  Please see C of A for spin curve for your ink
CAMBRIOS CONFIDENTIAL
Metal Ink Preparation Procedure
Remove bottles from cold storage
Allow bottles to come to room
temperature BEFORE opening bottle
Agitate contents to remove
sedimentation:
stir bar or propeller for 30 min. @ 100 – 200
rpm (DO NOT SONICATE)
Pour desired quantity of Metal Ink used
for experiment in dry, clean bottle and
store unused amount in refrigerator
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Filter only if necessary (please refer to
notes on pg. 9)
OPTIONAL: Degas at 10 psig for 60
minutes
(Degassing helps remove bubbles that may appear
as coating defects)
Metal Ink Coating Guidelines
•  Typical coating conditions used at Cambrios to report data
–  Substrate: Corning Eagle 2000 glass
–  Substrate size: 150 mm x 150 mm
–  Dispense volume to cover entire substrate: 10 cc, dispense while
substrate at rest
–  FILTER (if necessary, see notes on page 9)
–  Spin acceleration: 1000 rpm/s
–  Spin time: 60 s
–  Exhaust, air flow and chuck design impact coating uniformity and
coating quality and must be optimized depending on coater and other
conditions
–  Substrate is removed from spin coater and dried
–  Drying conditions: oven dry at 50 C for 90 s
•  Proper drying conditions can have big impact on film appearance and
uniformity
–  Soft bake: hotplate bake at 180 C for 90 s
•  If using low temperature substrate, can also softbake as low as 120C for 5
min.
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Typical Spin Curve
CAMBRIOS CONFIDENTIAL
Range of Accessible Sheet Resistances
•  A wide range of sheet resistances are accessible using other formulations and spin coating
conditions
•  Contact Cambrios regarding specific recipes to achieve the range shown in the graph above
CAMBRIOS CONFIDENTIAL
Coating Procedure Notes
• 
Filtering: metal ink solution can be filtered in-line during dispensing or off-line prior to
dispensing –
–  For larger volumes, Cambrios recommends filters with pore size no smaller than 75 micron
nominal
–  For small volumes or laboratory scale coating, syringe filters with nylon mesh membrane
with mesh sizes in the 20 micron range can be used.
• 
Drying: conditions for metal ink depend on user’s substrate and other parameters
–  Cambrios recommended conditions are only a guideline
–  Drying conditions can affect not only film appearance (mura pattern etc.) but also film
conductivity and haze
–  User needs to optimize drying conditions for best performance
• 
Metal ink soft bake: softbake of metal ink lowers and stabilizes sheet resistance.
–  Baking is a time/temperature product; for high temperature substrates, Cambrios
recommends 180 C for 90 s. If using low temperature substrates such as PET, can lower
temperature to 120 C and increase time to 5 min.
• 
For all drying and bake steps, Cambrios uses convection oven
CAMBRIOS CONFIDENTIAL
Recommended Measurement Methods
•  4-point probe with large tips
is recommended for best
results
  For example R-Check unit shown
here
Probe pins
•  Non contact measurement
systems provide best results
  For example Delcom 717b Bench
Top Conductance monitor
depicted here
http://www.delcom-inst.com/717B_Brochure.htm
Cambrios Confidential
Pattering ClearOhm™ Layer
CAMBRIOS CONFIDENTIAL
ClearOhm™ Patterning Guidelines
•  If patterning process is needed:
–  Follow guidelines as described for coating metal ink layer
–  Pattern according to standard photopatterning process
•  Cambrios has most experience with particular type of
patterning chemicals (described in following pages)
–  Other chemicals are also possible however user must check with
Cambrios regarding compatibility prior to use
CAMBRIOS CONFIDENTIAL
ClearOhm™ Patterning Process
METAL INK
PATTERNING
Coat PR
Substrate clean
Softbake
Dispense metal Ink
Expose
Spin coat
Post exposure Bake
Dry
Develop- DI Rinse
Softbake
Etch- DI Rinse
Strip – DI Rinse
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Cambrios Recommended Chemicals and Process
Conditions
• 
Spin coat AZ-3330F photoresist
– 
• 
First bake
– 
• 
AZ300MIF developer, puddle 30sec., DIW rinse-30secs, spin dry, repeat 15s
Etch
– 
• 
110C, 60sec. on hot plate
Develop
– 
• 
Contact masking, 17 sec. @13mW/cm2
Second bake
– 
• 
110C, 180 sec. on hot plate
Expose (i-Line)
– 
• 
2000rpm/1000ramp/60 sec./10mL – 2.5µm
Aluminum etchant, 60 sec. puddling, DIW rinse-30secs, spin dry
Strip
– 
PGME used as stripper to strip photo resist
– 
Acetone for 25 sec. , spin dry 30 sec., repeat once
OR
• 
Clean the backside of the plates (if necessary)
• 
Overcoat
OTHER CHEMICALS AND PROCESSES ARE POSSIBLE PLEASE PROVIDE US WITH DETAILS
FOR YOUR PROCESS FOR FEEDBACK
CAMBRIOS CONFIDENTIAL