HI,

I have a wafer with trenches that are 3 um deep and 20 um wide.  I
want to planarize the wafer using a CMOS compatible material while not
exceeding a temperature of 650C.

I presume I cannot use BPSG for this purpose since it reflows only at
950C.I could use Polyimide but I am not sure if it is CMOS compatible.

Can anyone please suggest an alternative that suits the above requirements.

Thanks
Kamesh