From maryamzm at stanford.edu  Tue May  6 17:07:30 2008
From: maryamzm at stanford.edu (Maryam Ziaei-Moayyed)
Date: Tue, 06 May 2008 17:07:30 -0700
Subject: oxide wafers
Message-ID: <20080506170730.6ck154bpwoogskks@webmail.stanford.edu>

Hi Mary,

Could we get some oxidized wafers for lampoly cleans? Maybe Nancy has  
some oxide wafers from her oxidation qual runs.

Also I've noticed that some people run long etches without cleaning  
the chamber afterwards. Also everyone please run at least one clean  
(PROGRAM 99) after long etches.

Thanks,
Maryam



From mtang at stanford.edu  Wed May  7 08:17:03 2008
From: mtang at stanford.edu (Mary Tang)
Date: Wed, 07 May 2008 08:17:03 -0700
Subject: oxide wafers
In-Reply-To: <20080506170730.6ck154bpwoogskks@webmail.stanford.edu>
References: <20080506170730.6ck154bpwoogskks@webmail.stanford.edu>
Message-ID: <4821C7EF.6090003@stanford.edu>

Hi all --

Yes, my bad.  I pester Maurice/Nancy for LTO dummies for lampoly cleans 
and will do so.  Yes, the cleans aren't being done now because the 
recipe #99 appears to fault.  Looking at it yesterday, the recipe faults 
for pressure control, but the pressure control is actually quite good 
and I'm pretty convinced that the problem is something else altogether, 
although it manifests as the common pressure faults.  This recipe also 
repeatedly gets the 217 fault -- which I suspect may be because it is 
lacking an extra step to allow for He clamping.  I'll try to look at it 
again today. 

I think we should be OK for a while without cleans, because the chamber 
was very recently scrubbed.  Drastic changes in DC bias for a given 
recipe/wafer type should indicate excessive buildup.

Everyone, please report any faults you get -- and your observations 
(including the recipe run and when during the run the fault occurs) in 
the logbook or Coral (though both would be ideal.)

Thanks,

Mary

Maryam Ziaei-Moayyed wrote:
> Hi Mary,
>
> Could we get some oxidized wafers for lampoly cleans? Maybe Nancy has 
> some oxide wafers from her oxidation qual runs.
>
> Also I've noticed that some people run long etches without cleaning 
> the chamber afterwards. Also everyone please run at least one clean 
> (PROGRAM 99) after long etches.
>
> Thanks,
> Maryam
>


-- 
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



From mtang at stanford.edu  Fri May  9 13:55:50 2008
From: mtang at stanford.edu (Mary Tang)
Date: Fri, 09 May 2008 13:55:50 -0700
Subject: Lampoly particles
Message-ID: <4824BA56.8090200@stanford.edu>

Hi all --

We've just learned from the more experienced Berkeley folk that the 
black particles observed by a couple of people this week are actually 
redeposited buildup from extensive use of the HBr-only recipe, without 
alternating with the clean recipe.  Since the clean has been faulting 
during the etch, we have not been able to run the full clean recipe.

I've just put the system down.  Apologies for the inconvenience, but we 
don't want to risk contaminating people's wafers.  The system is 
undergoing chamber purge now and the chamber will be cleaned first thing 
Monday (thanks Elmer).  We will also work on troubleshooting the clean 
recipe failure, which appears it might be an RF problem which is 
manifested as a pressure control/turbo failure. 

We would greatly appreciate it if lampoly users could report process 
problems as they are observed.  If you have sample wafers or photos of 
the black particles, they would be much appreciated for our defect library.

Thanks,

Mary

-- 
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