> I would like to bond  SOI wafers (4") but one of them
> presents an important bow (190um).
> Do you know if we can find glue or glue-film or a specific
> bonding process to bond them?

Some of the bond chucks made by commercial vendors
have an intentional curvature built in so that
the wafers first contact in the center,
allowing the bond front to propagate toward the edges.
You can probably order custom chucks for more curvature,
but be prepared to pay something like $15k.

        --Kirt Williams Agilent Technologies