To all Trion users,

I too have the Phantom II RIE with the load lock.  I have found that
etching III-V material was
impossible before I re-worked the system.  I found that their leak back
rate is so bad that it
puts too much air in the system while etching.  After taking the tool
apart and replacing all the o-rings I got a leak back of 1mT in 6.75
minutes.  This made all the difference in the world.  Selectivity
between resist and
what I was etching improved 5:1.  If you find your resist etching too
fast, check your leak back rate.

Brent