chronic HCl type of smell

Dick Crane rcrane at stanford.edu
Fri Mar 2 11:55:03 PST 2007


Investigated "chronic, HCl type smell" in L114-116, and 118 areas this 
morning. Four different noses could not detect any HCl type odor. All 
wetbenches were checked for proper exhaust draw using an anemometer. 
Flows were good. Checked furnace exhausts, no anomalies were found. 
Weekly burnbox clean was due this morning, but normal pressures were 
observed. Suggest we keep a nose out for any additional events.

Possible odor sources might be:
Outside odors drawn into the fab.
User not following wetbench/chem handling protocol.
Furnace burnbox overpressurizing and leaking.
APfurnace end plate not sealing during TCL clean.
Ripe bunnysuit. (No kidding, I once located that as a source).

Dick

Robin King wrote:

>Hi,
>
>Uli suggested I write to this group.  Right now and occasionally
>recently there has been a low-grade HCl / seaweed kind of smell that
>comes and goes, near wbsilicide and the LPCVDs, and also a little by
>wbdiff.  Not everyone can smell it, but after Jim McV and Uli checked
>it out, Josh (student) came by and said he clearly smelled it.  
>
>Tylan4 is running with tlcclean, BUT it's just started with no TLC
>yet and the smell came before that.  Wbsilicide hotpots are cold. 
>Wbdiff HCl pot was changed at 2:30pm and is hot. The flow seems good
>into the wetbenches.
>
>I wanted to let you know so this problem can be tracked down.
> 
>Thanks,
>
>Robin King
>
>
> 
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