James Conway jwc at
Tue Jan 25 19:32:42 PST 2005

See me tomorrow PM and I will figured out the dilution ... EZ to 
prepare. Not a problem.
I have a stock of 9% 950K PMMA in chlorobenzene that I use for dilution 
down to custom viscosities.
I have 1.25 and 1.50 % 950K PMMA in several small batches prepared for 
my Scanning Probe Lithography collaboration with U Nevada-Reno.

The 2% 950K MW PMMA  we purchase prepared from Microchem; so I don't 
have to make it myself.

Here are the curves you desire.  [web link:  [ Single Layer aka 2% 950K 
] [5% 495K PMMA 


I am currently working on characterizing the anisole resist materials.  
I recently placed 2% 950K MW PMMA-anisole and 5% 495K MW PMMA - anisole 
in the solvent cabinet in the rear FAB chase for people to get started 
with their own process characterization.
 Microchem went to great effort to produce nearly identical materials.  
Have been working with these materials in Dortmund, DE and they are 
nearly the same. Remember the solvent is just a transport vehicle and 
once cured its the same stuff, i.e, PMMA

Will post the PMMA anisole spin speed (f) thickness curves, optimized 
doses, and contrast curves just as soon as I finish the work. In coming 
week(s)...  If people wish to take a spin with me they are welcome. Sign 
up is in my office or see me during my office hour.

We will also maintain a supply of the Chlorobenzene based system for 
reference and critical project needs until we use up the supply. Likely 
we will overlap and have both in house through the next few weeks to a 

 I also have a number of silicon wafers with various thickness including 
the spec. thickness in my collections. Happy to share with anyone 
needing these if you will report the data and results obtained.


Thank you and good evening,

James Conway

Dirk Englund wrote:

> Hi James,
> Could you mix a rather small amount of high-molecular weight (the one 
> that's normally used for 2% I believe) down to 4%?  We want to get 
> about 300nm thickness on GaAs samples.  So far, we've been using 2%, 
> but it coats too thin.  And I'd like to stick with high molecular 
> weight since the recipe is already worked out for it and it's higher 
> accuracy.  So if you give us the solution, I can spend a few hours 
> measuring a calibration curve.
> Also, you just mentioned on the phone that other cal. curves are 
> posted on the web -- could you tell me where?
> Thanks
> Peace--
> Dirk

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