Question: Need to backside etch after about 3um LPCVD LTO deposition?

Dear labmembers,

 

I had deposited 3um LPCVD LTO on the silicon wafers.

The next several steps for the wafers include ASML lithography and STS DRIE.

In this case, should I etch out the oxide on the backside of Si wafers? Or can I use ASML and STS DRIE without backside etching on sample wafers?

 

Thanks,

Kyunglok