BCl3 status on P5000etch and pquest

[Mary Tang]

Hi all --

BCl3 has been turned back on P5000etch and Pquest.  No, this is not the 
new cylinder, which is still in transit from the East Coast (no delivery 
date as yet).  This is the same cylinder which we received and found to 
be contaminated.  BCl3 is a low vapor pressure liquid source (4.4 psig) 
and we were able to determine that the cylinder appears to have been 
charged with an apparently innocuous gas.  Elmer did extensive pumping 
on the cylinder to flush the gas and purged the gas lines.  The plasma 
has returned to a normal color and Nancy's Al etch rate qual on 
p5000etch now looks really good.

Full disclosure:  by available measures, the BCl3 appears to be OK.  
However, this experience leaves some concern about the integrity of this 
cylinder, so we still plan to replace this cylinder with the new one 
when it arrives, to put any lingering doubts to rest.  Please make sure 
to run a test sample before committing your own material to a critical 
etch.  Please also report any issues on Coral.

And by the way, P5000etch users:  ChA is back online with a replacement 
turbo controller.

Thanks for your attention and patience --

Team Etch

-- 
Mary X. Tang, Ph.D.
Stanford Nanofabrication Facility
Paul G. Allen Room 136, Mail Code 4070
Stanford, CA  94305
(650)723-9980
mtang at stanford.edu
http://snf.stanford.edu