> 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