TXRF results for continued processing on semi-clean tools...

Ed Myers edmyers at stanford.edu
Fri Oct 9 10:48:27 PDT 2009


Likewise, I've talked with Robert regarding this request.  He is not 
certain he needs the system, and he won't if we get the new 610's in.

Ed

At 09:21 AM 10/9/2009, Mary Tang wrote:
>And Robert?
>
>Mary
>
>Robert Huang wrote:
>>
>>Dear SNF Specmat Committee Members:
>>
>>
>>
>>I would like to ask for the committee's approval to run 4" silicon 
>>wafers on SNF semi-clean tools (mainly the AG4100 RTA machine) that 
>>have been deposited with titanium oxide via e-beam evaporation 
>>through an external vendor.  We have worked with this vendor to 
>>reduce metal contamination levels below the 1e12/cm2 "semi-clean" 
>>specification limit.  As you will see in the attached file, prior 
>>to taking corrective action, there were locations on a test wafer 
>>that clearly exhibited Fe and Cu levels above the 1e12/cm2 
>>limit.  However, after detailed investigation, several steps were 
>>taken to clean up the tool with the positive results shown in the 
>>attached file from the last test wafer.  Note that the TXRF results 
>>were provided by Evans Analytical Group (EAG) using a W source 
>>which can detect elements from S-Zn and Mo-Hf.  If an element is 
>>not listed in the table, it was not detected in the 
>>analysis.  Evans has a detailed procedure for calibration of their 
>>TXRF equipment and guarantee reproducibility to within the reported 
>>results (uncertainty values in the table are 1sigma standard 
>>deviations) through use of calibrated Vanadium and Nickel 
>>references.  Also note that due to overlap in emission energies, 
>>EAG can only report upper bounds for some of the elements 
>>(specifically the Cu and Hf energy peaks overlap) and the 
>>background matrix Ti energy peak interferes with the Cl, K, and Ca peaks.
>>
>>
>>
>>If there are any questions, please do not hesitate to contact me.
>>
>>
>>
>>Sincerely,
>>
>>
>>
>>Robert Huang
>>
>>Director, Process and Device Technology
>>
>>QuSwami, Inc.
>>
>>505 Montgomery St., Suite 300
>>
>>San Francisco, CA 94111
>>
>>415-834-9910 (Office)
>>
>>408-854-0450 (Cell)
>>
>>roberth at quswami.com <mailto:roberth at quswami.com>
>
>
>--
>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





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