using mercury dibromofluorescein disodium salt in SNF...

Robert Huang roberth at
Tue Sep 8 13:31:56 PDT 2009

Hi Mary,

Yes, amazing that it is the same as what was widely used by many (including myself!) in the "old" days.  To answer your questions:

1)  If I successfully prove the technique (which is likely since it has been published and done by others), I will probably run it a few times over the next 2-3 months.

2)  It does not need to be in the yellow room.  I was thinking to use it at wbgeneral.

3)  To start, I will use enough to immerse 1 to a few wafers at a time in the solution.  Physical hardware may limit me from doing any more than a few at a time.

4)  Coating will be done at room temp.

5)  No other materials required (other than DI water to get it into solution).

6)  Yes, I would like to store the material at SNF.



-----Original Message-----
From: Mary Tang [mailto:mtang at] 
Sent: Tuesday, September 08, 2009 12:49 PM
To: Robert Huang
Cc: specmat at
Subject: Re: using mercury dibromofluorescein disodium salt in SNF...

Hi Robert --

Gee, reading the MSDS, you wouldn't think this was the stuff that our 
moms used put on cuts and scrapes. But it was taken off the market for a 

First, some questions:

1. How often will this be used? Is it a one-time test or do you 
anticipate frequent use?

2. Where will this be used? Does it need to be in the yellow room?

3. How much will you use? Enough to cover one wafer or 25?

4. Is this heated or at room temp?

5. Are there any other chemicals required for this process?

6. Do you plan to store the material at SNF?


Robert Huang wrote:
> Dear SNF Specmat Committee:
> I am interested in using mercury dibromofluorescein disodium salt 
> inside the SNF facility. First question - Is it perhaps already on the 
> approved list of materials that can be used in SNF? If not, I would 
> like to ask the committee's permission to use. My intent is to 
> dissolve the salt in DI water and submerge my 4" silicon wafers in the 
> solution in order to coat my wafers with the resulting photosensitive 
> material. Other names for this compound are:
> 1) 2',7'-Dibromo-5'-(hydroxymercurio)fluoresceindisodium salt
> 2) Merbromin
> 3) Mercurochrome
> I'm attaching the MSDS from Sigma-Aldrich which is where I plan to 
> obtain the material. You can also obtain the document from their 
> website - <>, using 
> product #M7011.
> If any questions, please don't 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 <mailto:roberth at>

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

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