Note to Users on the two blends of Microchem 5% PMMA in Anisole. Two different molecular weights are available for your usage.

James Conway jwc at snf.stanford.edu
Fri Jan 25 10:49:00 PST 2008


Good Morning to all SNF 5% PMMA Users:

I just wanted to remind All PMMA Users that we currently have in the 
Cleanroom two blends of 5% PMMA in Anisole manufactured by Microchem:

1.  5% 495K Molecular Weight PMMA in Anisole 
<http://snf.stanford.edu/Process/Lithography/EBResist/5P495kMWPMMA-Anisole.pdf> 
-- This is our standard PMMA resist and if you use the default spin 
speed in our process sheet you will obtain thin films on the order of 
300 nm in thickness.
     This is suitable for fine lines down to below 50 nm and should be 
employed if you are performing metal lift-off with stack thicknesses 
greater than 200 nm, or if you prefer to perform RIE for etch processes 
as deep as 400 - 500 nm into Silicon.  This material can also be 
employed as the lower layer in a dual layer stack for thick metal lift 
off processing.

I have stocked a new bottle of this material into the SNF cleanroom 
yesterday and it is from the same Microchem Batch Lot number as the 
previous bottles we have had in the lab this last year.

2. 5% 950K Molecular Weight PMMA in Anisole 
<cid:part1.04010606.08020409 at snf.stanford.edu> - This material is the 
same PMMA material and is blended to the same 5% solids content in 
Anisole as the 495K, but formulated to a longer polymeric chain length 
which results in a higher molecular weight. It is suitable for all 
processes with the exception of the dual layer processes used for thick 
metal lift-off processing. In my initial measurements its spin speed as 
a function of thickness is slightly thicker than the 5% 495K PMMA 
material. My new Single Layer 5% 950K PMMA Ebeam resist process is 
attached as a MS word document for your review. 
Your comments are invited.

This material is currently under evaluation to determine if we can 
obtain improved performance leading to better ultimate resolution in 
feature size or an improved RIE etching characteristic.  I have this 
material currently stocked in the SNF Fab and Users are encouraged to 
give this material a trial using their patterns and processes. Please be 
sure to provide us with your feedback and images and data from your best 
results to add to SNF Ebeam Resist Process Suite on our website.

Thank you for your interest in Ebeam Technologies here at the Stanford 
Nanofabrication Facility,

James Conway






-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://snf.stanford.edu/pipermail/raith/attachments/20080125/ba718365/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Single Layer 5% 950K MW PMMA - Anisole.doc
Type: application/msword
Size: 1672192 bytes
Desc: not available
URL: <http://snf.stanford.edu/pipermail/raith/attachments/20080125/ba718365/attachment.doc>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Single Layer 5% 950K MW PMMA - Anisole.doc
Type: application/msword
Size: 1672192 bytes
Desc: not available
URL: <http://snf.stanford.edu/pipermail/raith/attachments/20080125/ba718365/attachment-0001.doc>


More information about the raith mailing list