README: ALL PMMA USERS IN THE LAB -- PLEASE REDUCE YOUR WASTE OF PMMA.

James Conway jwc at snf.stanford.edu
Wed Mar 15 18:34:33 PST 2006


Greetings PMMA Users working in the SNF Lab:

We have been going through both the 2% 950 K and the 5% 495K PMMA in 
Anisole at a much higher usage rate than is normal over the past years time.
In several cases the bottle in the lab has disappeared from the lab only 
to return several days later nearly empty.  250 ml is enough for 100 - 
150 wafers!

The last bottle of 250 ml of 5% 495K PMMA in anisole was exhausted in 
less than a month whereas before it would normally last for more than 
two months.

NOTICE TO ALL PMMA USERS IN THE LAB:
THE PMMA SUPPLY BOTTLES AND THE MATERIALS WITHIN ARE NOT TO LEAVE THE 
SNF LAB FOR ANY PURPOSE OR REASON.
USERS ARE REQUESTED NOT TO TAKE FROM THESE BOTTLES, OR MAKE UP SPECIFIC 
STOCKS OF PMMA AT OTHER VISCOSITIES FROM THESE SUPPLIES. If you need a 
custom formulary or viscosity please see me I have many viscosities 
already made up and available by sign out.

USERS ARE REMINDED THAT ALL [PMMA MATERIALS IN THE LAB ARE TO BE HANDLED 
IN SYRINGES] 
<http://snf.stanford.edu/Process/Lithography/EBResist/EBResistHandling.html> 
AND PIPETTES AND NEVER IS THE MATERIAL TO BE POURED INTO A BEAKER OR 
DIRECTLY ONTO THE WAFERS DURING COATING. NO EXCEPTIONS.

WHY:  IF YOU POUR YOU WILL LOOSE THE CONTROL OF THE VISCOSITY AS THE 
SOLVENT WILL RAPIDLY EVAPORATE. YOU WILL ALSO EXPOSE YOURSELF TO MORE 
SOLVENT FUMES THAN ARE NECESSARY ADDING TO YOUR RISK OF EXPOSURE TO 
SOLVENTS.

USERS ARE REQUESTED TO BE EXTRA VIGILANT, PARTICULARLY IN THE EVENINGS, 
AND TO INFORM ME SHOULD THEY OBSERVE USERS HANDLING THE MATERIALS 
INCORRECTLY OR IN A WASTEFUL MANNER.

The micro resist technology gmbH PMMA materials we employ here at SNF 
are the highest quality materials you can obtain anywhere.  But they are 
expensive to purchase and for us to suitably package for Lab use.

We have the normal OCG PMMA at similar molecular weights as the 
Microchem materials if you have the need for bulk PMMA coatings and I am 
happy to sign you out a bottle for this type of need.  I also have 
maintained a small supply of PMMA from before we switched over to 
Anisole last year that will soon expire.
Finally I have a large stock of 9% 950K PMMA in Anisole available for 
dilutions to lower viscosity if you need it.

NOTICE:
TODAY I PLACED A NEW BOTTLE OF 5% 495K PMMA INTO THE CLEANROOM.

IF MATERIAL CONTINUES TO BE REMOVED FROM THE LAB, OR SIMPLY WASTED BY 
CARELESS USERS, I WILL TAKE FURTHER ACTION TO CONTROL USAGE AND REDUCE 
WASTE; UP TO AN INCLUDING LOCKING UP ALL THE EBEAM RESIST.
 YOU WILL THEN HAVE TO CHECK IT OUT EACH DAY DURING MY OFFICE HOUR ONLY, 
AND AT NO OTHER TIME WILL IT BE AVAILABLE.  I DESIRE NOT TO HAVE TO TAKE 
THESE STEPS AS IT WOULD INCONVENIENCE EVERYONE.

PLEASE BE CAREFUL WORKING WITH THESE MATERIAL AND DO YOUR PART TO 
MINIMIZE WASTE OF THESE MATERIALS IN OUR LAB.

Thank you for your interest in Ebeam Technologies here at SNF.

James Conway


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