TXRF results for continued processing on semi-clean tools...
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.
At 09:21 AM 10/9/2009, Mary Tang wrote:
>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.
>>Director, Process and Device Technology
>>505 Montgomery St., Suite 300
>>San Francisco, CA 94111
>>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
>mtang at stanford.edu
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