Hi Helen,

in most cases room temperature bonding fails or results in a poor yield
because of the wafer roughness. Have you measured the AFM roughness? It
should be in the range of 0.5 nm. An CMP process might help to get the
required roughness.
Thickness of the wafer can influence the bonding result, especially if your
wafers have structures.

Are you talking about Pyrex glass or quartz when you say silicate glass ?

Markus.


SUSS MicroTec
Business Field MEMS
Markus Gabriel
Schleissheimer Str. 90
85748 Garching
Germany
Fon     +49 89 32007 - 313
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http://www.suss.com/mems




Hi All,

I am trying the glass-glass direct bonding on my wafer
(silicate glass). I
read about the precess consisting of

(1) hydrphilization: with H2SO4:H2O2, or
H2O2:NH4OH:H2O
(2) bonding: light pressaure applied in the center of
the wafer, achieve
        bonding across the whole wafer at room
temperature
(3) annealing: 350 deg C for hours to stabilize the
bonding

I tried but failed. Does anyone have success in
glass-glass direct
bonding? My questions are:
what is the ratio of the mixture for hydrophilization?
Is that very critical?
What is the proper pressure to apply?
Has any one achieve the bonding using EV bonder? Can
you tell me some more
about the process? Does the wafer size and thickness
matter?

Thanks so much for your help.

Best,
Helen