New chemical approval request : Poly(styrene-b-methyl methacrylate)

Mary Tang mtang at
Tue Jan 11 07:13:17 PST 2005

Hi Li-Wen --

Thanks for your request. In principle, your PS:PMMA is fine to use in
the lab. However, there are additional considerations:

1. The TylanFGA tube is NOT what you want to use. This probably goes too
high for what you want (you'll char your polymer) and your material will
then contaminate the tube. Please review the procedures available
on-line for processing PMMA. There are a couple of BlueM ovens available
which are likely more appropriate for your needs. Let us know what
temperature process cycle you require for the PS/PMMA material. Please
also be aware that because you are using toluene, that you'll have to
take special precautions to ensure that your uncured material is always
kept either under an exhausted bench work area or in an enclosed box. We
do not want toluene vapors in the lab.

2. Make sure to review the MSDS for toluene. PS:PMMA is pretty inert --
toluene is not -- although you find it everywhere, it should be handled
carefully. Most MSDS sheets will not state this, but it is a suspected
carcinogen and should be handled only in a solvent hood. There is a
solvent hood available in the wafersaw room which you can use for mixing
your solutions. There is also a small scale there which you can use for
weighing. You will probably have to find your own labware to measure,
mix, and store your solutions.

3. The AFM, ellipsometer, and SEM should be used only on the cured material.

4. You will need a yellow Personal Chemicals label for each of your
PS:PMMA/Toluene bottles, if you plan to store this in the lab. If you
plan to dispose of it the same day you use it, then you can just use a
standard blue hazardous chemicals label. Please see Mahnaz about getting
a yellow label, if you need it.

5. You will need to take precautions in disposing only of the uncured
material. At the headway, solid waste should be enclosed in a sealed
plastic bag and then placed in the solid waste container for solvent
waste, under the lithosolv bench. Any liquid waste may be disposed of in
the solvent carboy at the lithosolv bench.

In summary, your request is not approved until you take care of #1 and
you understand and agree to abide by #2,3,4 & 5. Discuss your curing
cycle with Mahnaz and see if the standard PMMA process tools will work
for you.


Li-Wen Chang wrote:

> Dear sirs:
> I have a request for approving a new chemical : Poly(styrene-b-methyl
> methacrylate) which is a kind of diblock copolymer.(PS:PMMA).
> Please review the following information.
> Tks.
> 1. Requestor name: *Li-Wen Chang*
> 2. Phone number: *650-387-6139*
> 3. email address: *lwchang at* <mailto:lwchang at>
> 4. Requestor’s PI (Advisor) or Company:
>     *H.-S. Philip Wong
>     Center for Integrated Systems, CISX 312
>     Stanford University, Stanford, CA 94305.
>     Phone: +1-650-725-0982
>     Fax: +1-650-725-7731
>     Mobile: +1-650-353-0796
>     Email: hspwong at *
> 5. The name of the new Chemical (give all names commonly used):
>     *Poly(styrene-b-methyl methacrylate)*
> 6. If there are secondary new chemicals that must be used with this
> material, such as a developer for a new resist, list each of them here
> and supply MSDSs for each of them.
>     *N/A.*
> 7. Name of vendor/manufacturer that you are planning to obtain this
> material from:
>     *Polymer Source Inc.*
> 8. URL for vendor’s website where info on the proposed chemical can be
> found:
>     **
> 9. Vendor’s address and phone number:
>     *124 Avro Street
>     Dorval (Montreal), Quebec H9P 2X8
>     Canada*
>     *Toll Free: 1-866-422-9842
>     Telephone: 514-421-5517 or 5506
>     Fax: 514-421-5518
>     E-mail: **contact at*
>     <mailto:contact at>
> 10. What is your reason for wanting to bring this material into the lab:
>     *Quantitative investigation of lithographic subdivision using
>     self-assembly diblock copolymer*
> 11. Make a strong case why you can not use an already approved
> chemical/material for this purpose:
>     *Poly(styrene-b-methyl methacrylate) has self-assembly property
>     and has the potential to integrate to semiconductor process. We
>     want to explore the process space of self-assembly
>     Poly(styrene-b-methyl methacrylate).*
> (Note that all previously approved chemicals are listed in the MSDS
> Index binder located in the receiving area. Also see SNF Index of MSDS
> Sheets <>.)
> 12. List all the lab equipment
> <> and wet benches
> that you propose to use with this chemical:
>     Optical Photolithography Resist Coat - *Headway Coater*
>     <> .
>     Exposure - *Karl Suss MA-6 Contact Aligner*
>     <> .
>     Annealing Furnaces - *Tylan Forming Gas Anneal*
>     <> .
>     Wet Benches - *General Use Wet Bench (wbgeneral)*
>     <> ;
>     *Solvent Wet Bench*
>     <> .
>     In-Line Process Characterization *AFM Nanoscope Dimension*
>     <> ; *Rudolph
>     Ellipsometer*
>     <> ;
>     *SEM Hitachi Model S-800*
>     <>
> 13. Proposed quantity of the chemical that you want to bring into lab
> (give both raw and mixed quantities):
>     *Mixed quantities : approximate 200ml . (The raw material is in
>     the form of powders and is not permitted in the cleanroom.)*
> 14. State the form that the proposed chemical is in. (Is it solid,
> powder <> or liquid?
> Note: as a general rule, powders
> <> are not permitted in
> the cleanroom.):
>     *powders*
> 15. State whether the chemical needed to be mixed to use it:
>     *To mix up the powders using toluene into a solution.(Need access
>     to a chemicals handling bench.)*
> 16. From manufacturer, vendor or the Stanford safety site
> <>, obtain a legible Material Safety
> Data Sheet (MSDS) for all the proposed chemicals. Send these to the
> person listed below.
>     *As attached files. (SMMA)*
> 17. If the chemical/material is to be used in any the "clean"
> <>
> equipment, purity specifications will be needed. This is most
> important for chemicals/material that are not normally used for VLSI
> device fabrication. To be allowed into a "clean" tool
> <>, the
> material should MOS grade or better.
> 18. Read the MSDSs as well as the Stanford Chemical Storage Groups
> <> and the Stanford
> Chemical Safety Data Base
> <> sections on
> this website to determine the Storage Group Identifier
> <> and Main Hazard
> Class <> of your
> chemical/material.
>     *L Solvents, Flammables, and Combustible Materials. Main hazard
>     class : 0.*
> 19. Determine whether there is enough room to store your material in
> the designed lab storage areas. Storage groups
> <> A,B,D and L are
> stored in the yellow solvent cabinet in the furnace support area,
> while storage groups
> <> C, E, F and G
> are stored on top of one of the Pass-through Carts. Ensure your
> chemical container or material is properly labeled
> <>. If there is no
> available room, it must be stored by in the bulk storage area. You
> will then need to obtain it from receiving area personnel each time
> you want to use it and return it to them when you are finished using
> it (or each time you leave the lab). Note that there is no storage of
> chemicals/materials in the processing lab or at any wet bench.
>     *Stored in the yellow solvent cabinet.*
> 20. In your discussions with vendors, try to determine the best way to
> dispose of your spent chemicals and by-products. The lab has
> acid/base, HF and solvent drains. The acid/base drains go to a
> neutralization system before going the city waste water system. The
> city of Palo Alto has tight limits on the amount of heavy metals that
> be disposed of through the waste water system. If your chemical
> contains any metals, there is a good chance that you will have to
> collect all your waste and dispose of it in labeled containers which
> are picked up the Health and Safety Department. The HF drains go to a
> central tank which is pumped out by a HF disposal service at
> considerable expense on a regular basis. The solvent drains in the
> solvent benches are collected under the benches and disposed of by
> Heath and Safety as needed.
>     *Contact a licensed professional waste disposal service to dispose*
>     *of this material. Dissolve or mix the material with a combustible*
>     *solvent and burn in a chemical incinerator equipped with an*
>     *after burner and scrubber. Observe all federal, state, and local*
>     *environmental regulations.*
> 21. Put together a detailed process flow description on how you
> proposed to use this chemical. This should include: Any chemical
> mixing, all lab equipment and wet benched to be used, all containers
> to be used, where chemical is to be stored and how chemical and
> by-products are to be deposed of. This should be in a Word file
> attached to your e-mail request. In reviewing your procedure, we will
> be most interested in how the safety and contamination issues are to
> be dealt with.
>     *As attached file. (flow)*

Mary X. Tang, Ph.D.
Stanford Nanofabrication Facility
CIS Room 136, Mail Code 4070
Stanford, CA  94305
mtang at

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