Iodic Acid

Mary Tang mtang at stanford.edu
Tue Mar 17 13:39:40 PDT 2009


Looks good to me -- any objections, SpecMat'ers?

M

Mike Wiemer wrote:
>
> Iodic Acid Procedure
>
> 1.) We will mix the powder into solution using the acid hood in the 
> dicing saw room (0.2M/L solution).
>
> 2.) The powder will be stored in the acid vault.
>
> 3.) The acid will be brought into the lab either through the chemical 
> passthrough or the cleanroom “back door” using a bottle carrier
>
> 4.) The mixed acid will be stored in the chemical passthrough in a 
> dark brown bottle (with a yellow label of course)
>
> 5.) All etch waste will be collected and tagged and placed in the 
> proper chemical passthrough area
>
> 6.) Waste acid which has not etched material will be aspirated
>
> Approved?
>
> Thanks!
>
> -Mike
>
> *From:* Mary Tang [mailto:mtang at stanford.edu]
> *Sent:* Tuesday, March 17, 2009 9:53 AM
> *To:* Mike Wiemer
> *Cc:* specmat at snf.stanford.edu; Senyo Dogbe
> *Subject:* Re: Iodic Acid
>
> Hi Mike, Senyo --
>
> Thanks for the reminder... Just a couple of things.
>
> 1. Powders (including crystals -- as well as free nanoparticles and 
> nanotubes) aren't allowed in the cleanroom. It's just too difficult to 
> handle powders (dispensing, weighing, mixing) when there's laminar 
> flow and exhaust blasting in different directions. You can, however, 
> mix solutions from powders outside the cleanroom, in the wafersaw 
> room, and bring them in, either through the chemicals passthrough (get 
> a staff member to help you with access) or using a single bottle 
> carrier through the service area in the back. Alternatively, if you 
> can find a source of pre-mixed solution, you won't have to mix it up 
> yourself.
>
> 2. Can you store the solution for an appreciable time or does it have 
> to be mixed up just before use? If you store the bottle of solution, 
> it should be kept in the chemicals passthrough. Make sure to get a 
> yellow label. I take it that a brown bottle should be sufficient for 
> excluding light -- if you decide to also wrap it in foil or other 
> covering, make sure to label the outside of the foil with all the 
> critical info as well.
>
> 3. Crystals should be stored outside the lab. We have a corrosives 
> room where this can be stored. However, you'll need staff help to 
> access the vault, so this will limit availability to working hours.
>
> 4. How will you be disposing of the waste? If you are etching III-V's, 
> then etchant waste should be collected locally and appropriately 
> tagged. The unused acid itself, I believe, can disposed of by 
> aspirating at the bench.
>
> 5. Could you write up a procedure for this (like what you have below, 
> but with the where's and how's)?
>
> Thanks,
>
> Mary
>
> Mike Wiemer wrote:
>
> Hi Specmat,
>
> We would like to use Iodic Acid in SNF. This chemical is commonly used 
> as an echant for III-V materials like InP. MSDS attached.
>
> Iodic Acid comes in dry crystal form
>
> One mixes the crystals with water to form the acid (0.2 M/Liter) in a 
> glass, non-transparent bottle (Iodic acid should be kept from light)
>
> We will mix the crystals & water to create the solution at the GaAs bench
>
> At the GaAs bench, we will combine: HIO3 (0.2M/L) : HCl : H2O - 1:1:x 
> where x goes from 1 to 100.
>
> All work will be done at room temp
>
> We will store the mixed solution in the personal chemical pass-through 
> area, along with the dry crystals
>
> What do you think?
>
> Thanks!
>
> -Mike
>
>
>
>
> -- 
> Mary X. Tang, Ph.D.
> Stanford Nanofabrication Facility
> CIS Room 136, Mail Code 4070
> Stanford, CA  94305
> (650)723-9980
> mtang at stanford.edu <mailto:mtang at stanford.edu>
> http://snf.stanford.edu


-- 
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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