Fusion contamination classification

[Mary Tang]

Hi all --

My two cents'...  taking a conservative approach, I would suggest 
considering a rinse step before the Fusion step.  The reason is that if 
there is alkali metal (or other mobile ion) contaminant on the backside, 
even 120 C can be sufficient for driving in something deep enough to 
cause voltage shifts later in the process.  There might also be 
accumulated contaminants on the chuck/wafer handling tools which could 
transfer to wafers as they are processed on the system.

Taking a less conservative approach, we do not seem to have complaints 
about mobile ion contamination in our baseline now -- and we are 
vulnerable at the Gasonics, since temperatures can be quite high there 
-- and I'd suspect the Fusion would render wafers as susceptible as the 
Gasonics would.

Mary


Paul Rissman wrote:
> Hi All,
>
> We need to create a classification for the Fusion tool.  Since it is 
> in the lithography area and the temperature on the system will be a 
> maximum of 200 degrees, should it be considered un-classed as with 
> other litho tools?  It could potentially be used for cure for front 
> end implants.  Other likely uses are for harsh etches, e.g. stsetch.
>
> Paul
>


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