Hi all,

     We are using a RIE machine(Model:PX-1000, March company) for SiNx dry
etching (SF6+O2). The vaccum is achieved by a turbopump (Base presure of ~1
mTorr). The problem is that the turbopump is easily destroyed by the residual
materials produced during the etching process.

Here are our questions:

     1) whether the turbopump is not so suitable for this dry etching process,
or any special turbopump should be used here.
     2) Can we use a oil pump to replace the turbopump? any filter (what kind?)
should be used to avoid the impact of the residues?
     3) whether molecular pump can be used in this vaccum system. Our oil pump
seems much weaker than the turbopump(pump speed:16.6 m3/h < 30 m3/h).and how to
set up this vaccum system?

It will be very helpful and appreciated if someone can share the experience on
the vaccum system.

Thank you!

Geng Zhang