Hi,

Have anyone know about the mechanism of shower ehad surface got rough? I
experience this problem: for my PECVD Norvellus Sequel-2, the shower
head surface center get very rough after a couple of weeks, this cause
very high wafer to wafer uniformity for Teos process. I think my plasma
clean relate to this roughen shower head surface, but do not know what
exact causes this?

Thanks for your help.

Wendy