Hello Myong Kwon,

These size trenches are usually filled with the use of glass powder. There
are several methods of application.

1, With use of a silk screening method with the glass frit to apply then
heat to melt glass.

2,With  use of electrophoritically deposited glass via electric charge.
This technique may require some masking on the areas that you do not want
glass deposited on and one electrode in the solution and another to your
substrate. with the correct polarity glass particles in suspension are
attracted to your substrate and deposited. Then dry and heat to melt glass.

3, A possible squeegee or doctor blade of the frit suspended in a viscous
medium into the trench.

Spin on glass derived from metal alkoxides is not very suitable for filling
large gaps. The use of other Polymers in solution may suit you? There are
many that have an organic nature to them if this is not a problem there are
quite a few materials that may be used.

Are you looking for a pure quartz glass or can you use other glasses like
borosilicate, leadsilicate etc all which have different melting points?

Maybe you need the glass frit that has a similar coefficient of expansion
as your substrate.

Neal
Neal@zbzoom.net





At 10:56 AM 3/25/2005 +0900, you wrote:
>Dear Folks
>
>Dose anyone try to fill glass( type of powder, Spin on glass) into
>big trench(Width  : 250um, Depth : 750um) of silicon wafer?
>
>I'm looking forward to reply. Thanks in advance
>
>Koo, Myung Kwon
>mkk999@mems-solution.com