Spin Coating PEDOT:PSS
Spin Coating PEDOT:PSS
(OP)
I have got a Si wafer 4" in diameter. I am cleaning it using Piranha solution. I am spin coating water soluble PEDOT:PSS on top of it with static dispensing ( I am dispensing the material around 5ml before the spin starts). The material I deposit covers the substarte completely. I am spinning at the speed of 4000 rpm for 1min.
The issue is I am always getting comet tail defect or streak through out the wafer after spinning.
Before spin coating I am using syringe filter to filter out the particles from the solution. I am using a laurell 400 lte spin coater without a fragment adapter. I am just lying the wafer on chuck as the wafer is too big.
Please help. Your suggestions are highly appreciated. Please let me know IF I am doing anything wrong.
Best Regards
Prix
The issue is I am always getting comet tail defect or streak through out the wafer after spinning.
Before spin coating I am using syringe filter to filter out the particles from the solution. I am using a laurell 400 lte spin coater without a fragment adapter. I am just lying the wafer on chuck as the wafer is too big.
Please help. Your suggestions are highly appreciated. Please let me know IF I am doing anything wrong.
Best Regards
Prix





RE: Spin Coating PEDOT:PSS
Is it possible that the film top layer is crusting and you're seeing a wrinkling?
Have you talked to your spin coater's manufacturer, or talked to whoever has acquired Shipley or MacDermid? Their apps engineers might have some insight.
TTFN
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RE: Spin Coating PEDOT:PSS
Manufacturer has suggestion of playing with speed and time. I played with it. Its not helping.
RE: Spin Coating PEDOT:PSS
I did find this:
http://www.ossila.com/support/Fab_pedot_pss.php
also:
http://www.ossila.com/oled_opv_ofet_catalogue3/M12...
5000 rpm at 30s for that one.
TTFN
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RE: Spin Coating PEDOT:PSS
RE: Spin Coating PEDOT:PSS
Is your surface at a truly pristine level of cleanliness before dispensing? Is your Piranha fresh, with good peroxide? 3:1 ratio? Have you tried increasing your dwell time in the Piranha?
Alternately:
Are the streaks thinner or thicker than the main coating film?
Is your dispersion flocculating? ie - is it really homogeneous before dispensing? Loose flocs can reform fairly quickly.
RE: Spin Coating PEDOT:PSS
AT first I am using syringe to filter out the solutions...and then couple of minutes of stirring....and then finally spin coating it using static dispensing method
Thank You.
RE: Spin Coating PEDOT:PSS
RE: Spin Coating PEDOT:PSS
TTFN
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RE: Spin Coating PEDOT:PSS
@IRstuff- That might be the case...I am dispensing it manually using a 5 ml pipette..how to avoid this air during dispense...while dispensing I am keeping the tip at 1 cm above the substrate and dispensing it slowly..may be a pause in between just to verify there is no excess liquid...any tips on how to dispense it manually by avoiding air...
Automatic dispenser might solve this issue but I dont have one...
RE: Spin Coating PEDOT:PSS
TTFN
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RE: Spin Coating PEDOT:PSS
RE: Spin Coating PEDOT:PSS