PH3 alarm update

maurice stevens maurice at
Wed Nov 15 09:40:04 PST 2006

Many of you have noticed the PH3 mfc alarming at the end of runs in 
BPSG.  There was a zero drift... the mfc should have been reading zero 
flow but sometimes is would drift to 0.1 or 0.2.  There was never any 
gas flowing but the programmer is set to alarm if the mfc sees a flow 
when it should not see one.

Last week the mfc was replaced but this did not solve the problem.  Our 
local vendor (Tylan/Tystar?) is currently burning a new eprom that we 
hope will eliminate the problem.

We will update you when we have more info on this annoying problem.


maurice at

Maurice Stevens
Stanford Nanofabrication Facility
CIS Room 142, Mail Code 4070
Stanford, CA  94305
P. (650)725-3660
F. (650)725.6278

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