spec mat request: SCT Pt in Wbmetal

Mary Tang mtang at stanford.edu
Mon Nov 9 16:04:24 PST 2009


I had asked Mike to resend his memo announcing the semiclean B class of 
materials (from 2004!) and am attaching it here.  I believe the only 
change since then was to add Pd to the list of semiclean B materials 
(series of SpecMat requests in Jan. 2005.)

According to this -- and the discussions at the time, semiclean B 
materials were going to be allowed in Semiclean etchers (namely, 
amtetcher and p5000etch oxide chamber) because those etch chemistries 
should not chemically affect the materials listed (at least no more than 
other semiclean metals) and could be used as etch stops for making 
contacts.  I think we have, in fact, been allowing the UCLA gang to etch 
stop on semiclean B materials in p5000etch oxide chamber since this 
class of materials has been defined.

Rostam brings up a good question, though.  Can semiclean B Ti/Pt wafers 
be cleaned at wbmetal?  I don't think I could vouch for all the 
semiclean B materials on the list, but I would think that Ti/Pt would be 
pretty safe for the PRX and PRS chemistries. (I believe the UCLA gang 
has been cleaning their silicides at wbgeneral.)

Mary

Ed Myers wrote:
> The only concern I had was the oxide etch stopping on Pt in the AMAT 
> etcher.
>
> Nancy, what is the standing policy?
>
> Ed
>
> At 12:43 PM 11/9/2009, Mary Tang wrote:
>> Hi Rostam --
>>
>>
>> I realized that the wiki did not have the description of Semi-Clean B 
>> materials and so just posted it:
>> https://spf.stanford.edu/SNF/materials-and-chemicals/contamination-groups-at-snf/contamination-groups-for-controlling-process-flow-materials 
>>
>>
>>
>> Sorry about that.   According to this, your process is perfectly 
>> acceptable, provided your cleans are done in dedicated labware at 
>> wbgeneral or wbgaas.
>>
>>
>> What does everyone think about the proposal to clean these at wbmetal?
>>
>>
>>
>> Mary
>>
>>
>>
>> Rostam Dinyari wrote:
>>> Hi,
>>>
>>> I wanted to double check if I can do the following process. If some 
>>> parts of it are not allowed or I can do them with some alteration 
>>> please let me know.
>>>
>>> - diff clean wafers
>>> - lithography
>>> - deposit Ti/Pt in SCT
>>> - do a clean (ie semi-clean) lift off using clean beakers, etc
>>> - wbmetal prx127 (If I should, I'll change the chemicals with fresh 
>>> ones after using it)
>>> - wbmetal prs1000 (If I should, I'll change the chemicals with fresh 
>>> ones after using it)
>>> - deposit 50nm LTO in tylanbpsg
>>> - etch the oxide in AMTetcher and stop on Pt (If stopping on Pt is 
>>> not OK, how about if I don't etch all the way to the Pt)
>>>
>>> I know this is a short notice. I'd really appreciate it if you could 
>>> let me know your decision in ~ 2 days.
>>>
>>> Thanks,
>>> Rostam
>>>
>>
>>
>> -- 
>> 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
>
>


-- 
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

-------------- next part --------------
A non-text attachment was scrubbed...
Name: Semicleanb.memo.doc
Type: application/msword
Size: 23040 bytes
Desc: not available
URL: <http://snf.stanford.edu/pipermail/specmat/attachments/20091109/9298c233/attachment.doc>


More information about the specmat mailing list