Hello,

I'm interested in defining/estimating the wedge angle of MEMS chips from wafer
specification. I talked to a few wafer suppliers and found out that  there is no
direct specification on the chip wedge angle.  The most relevant  spec is Total
Thickness Variation (TTV). However, with a given TTV spec, the nature of TTV
profile a cross a wafer will affect wedge angle of chips greatly. I tried to
find information about the nature of TTV profile of wafers but with little luck
so far. Any information about chip wedge angle or TTV profile estimation will be
appreciated.

Thank you.

Wenlin Jin