[labnetwork] expired process gas

[Kamal Yadav]

Hi,

I was also trying to find the affects of
expiration of NH3 and Diborane in Hydrogen and silane.

In pure gases it does not matter and you can use after expiration  we have
used 6 years post expiration for NH3.  When we changed new cylinder process
did not improve... So it does not matter.

In Diborane mixtures or similar I have been told that the ratio is not
maintained post expiration..

Thanks,
Kamal
IITBNF
 On Jan 10, 2015 3:45 AM, "Himmer, Phil" <PhilH at ee.montana.edu> wrote:

> Hello
>
>
> Thanks to all for your input about the expired gas. The general consensus
> is that expiration dates are not relevant for process stability so I’ll
> continue using what I have.
>
> regards
> phil
>
>
>
>
> Dr. Phillip Himmer
> Manager Montana Microfabrication Facility
> Montana State University
> Bozeman Mt 59717
>
> Office Ph: 406-994-7178
> email: philh at ece.montana.edu
>
>
>
> On Jan 7, 2015, at 2:44 PM, Janney, Peter J. <janney.9 at osu.edu> wrote:
>
>  It's my understanding that the gas doesn't really expire, it's only the
> certification on the tank.
>
>
>  --
> Pete Janney
>
>
> -------- Original message --------
> From: "Himmer, Phil"
> Date:01/07/2015 2:14 PM (GMT-05:00)
> To: labnetwork at mtl.mit.edu
> Subject: [labnetwork] expired process gas
>
>  Hello,
>
>  Does anyone have any practical experience using Chlorine and Hydrogen
> Bromide gas past it’s expiration date? We use the gas for ICP etching of
> chrome and aluminum.
> We have small cylinders(air liquide 7-size) of each that still have gas in
> them but are now years past the expiration date. I have pulled them from
> the gas cabinet with the plan to replace them but am having difficulty
> finding a vendor who offers these gasses in these small volumes. We are
> trying to not use lecture bottles due to disposal considerations.
>
>  looking forward to suggestions
> phil
>
>
>   Dr. Phillip Himmer
> Manager Montana Microfabrication Facility
> Montana State University
> Bozeman Mt 59717
>
>  Office Ph: 406-994-7178
> email: philh at ece.montana.edu
>
>
>
>
>
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>
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