SpecMat Logsheet, 10/12/05
edmyers at stanford.edu
Mon Oct 10 16:01:49 PDT 2005
Tuesday, 10/11 is our normal SpecMat meeting day. However many of us will
be involved with our visitors from Korea. I would like to propose we do
this meeting by email. We have three new items to address.
1) Jun-Fei Zheng: Poly deposition on a Vapor Jet Deposition Si3N4 film
from outside CIS. Jun-Fei is willing to provide TXRF data to show the film
meets our contamination requirements. The second part of the request is
"to avoid H2SO4:H2O2 process as our wafer has never been through
Lithographic process and this is what the H2SO4:H2O2 mainly for but
H2SO4:H2O2 process might destroy the gate quality Si3N4. We also do not see
the need for 50:1 HF dip, which is used for clear oxide formed on Silicon
during H2SO4:H2O2 process. We believe SC1 and SC2 in combination would be
able to address potential contamination during wafer handling and shipping."
Comments: The Thermcopoly tube is part of the Clean Equipment set and
requires a pre-diffusion clean prior to deposition. The request is use an
SC1/SC2 clean approach instead of the standard pre-diff clean. Is there a
bench were we can use SC1 (NH4OH/H2O2/H2O) and SC2 (HCL/H2O2/H2O) or will
the work need to be done in beakers?
2) Ching-Huang: McIntyre ALD Hf02 processing in Semiclean Tools. TXRF
analysis was provided with the request. The data shows the sample to be
above our SemiClean contamination specification for both Fe and Ca (along
with S). Do to peak overlap the levels of Ni, Co and Cu (possibly Cl)
could not be determined.
Comments: I do not think we should approve the request with this level of
contamination. I feel there should be an effort made to reduce the
contamination level in the ALD system before we assume the contamination
3) Mike Weimer: Limiting CF4 Etchs in pQuest. Etches using CF4 must
contain high amounts of O2. As a guideline (this number is not perfectly
strict, but is a good guideline) any etch with CF4 should be ~20% CF4 and
80% O2. Small variations around this % are OK. No etches containing large
amounts of CF4 and small amounts of O2 are allowed. This basically
eliminates etching of Si3N4 and SiO2 with CF4.
Comments: I do not think we should accept this proposal as presented
because it is to confining. I attended the meeting where this proposal was
developed. It is based on seen non-responsibility in the GaAs
etches. From the data that was presented, I was not convinced all the
non-reproducibility were caused by the CF4 etches. The GaAs community
was not willing to support testing of the memory effect in the chamber as
the gas chemistries are switched. The work was volunteered at not burden
to the GaAs community. I did volunteer to email the pQuest community with
any SpecMat request that come in. This way they can voice their concerns
early in the approval process.
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