Paul lots of things can cause a wafer to be hydrophobic then later to be
what I call resistaphobic.  Do you prime if so how long?  Do you keep a
record of humidity?  Is this or does this layer see any highly doped
phosphorus layer?

Bill Moffat

________________________________

From: [email protected] on behalf of Paul Nguyen
Sent: Thu 2/11/2010 6:47 PM
To: [email protected]
Subject: [mems-talk] resist peeled off as a sheet


Hello everyone,

I haven't seen this phenomenon but last couple of days 2 incidents have made
me wonder about the cause.  My wafer with 35um thick negative resist was
peeled off as a sheet after develop.  Anyone has any ideas of the causes?
More info: the wafer was SB with 2mins/67C and 8mins/125C, exp and PEB at
5mins/90C then develop; the wafer was cleaned and hydrophilic before
coating. Resist is BPR100.

Thanks in advance for any hints.

Regards,

Paul