How about spinning down some polyimide?
very simple

John

At 08:43 22/05/2002 -0700, you wrote:
> > I want to fill a deep trench in silicon wafer with insulating
> > material after Deep RIE process.
> > The depth and width will be around 300 micron and 500 micron,
> > respectively.
> > Does anybody know which process is available for that?
>
>Prof. Norman Tien's group at Cornell used a neat trick to
>fill a trench with oxide that might otherwise be unfillable:
>They used DRIE to etch a set of "fins" in the trench,
>then thermally oxidized these fins, turning the silicon into
>silicon dioxide and filling in the spaces at the same time.
>The ratio of silicon to space must be selected correctly
>for complete conversion of Si to SiO2, without leaving spaces
>after oxidation (the SiO2 takes about 2.2 times the original Si volume).
>
>         --Kirt Williams Agilent Technologies
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John Somerville
The Technology Partnership
Melbourn Science Park
Melbourn, Royston, Herts, SG8 6EE, UK.
Phone: +44 1763 262626
Fax: +44 1763 261582