Dear Dave,

Our xenon difluoride setup at Tohoku University has a small foreline trap
filled with molecular sieves.  The trap is used at room temperature.  This
trap eliminates the contamination of reaction chamber by the rotary pump oil
vapor.  The rotary pump oil is a standard one.  We haven't observed such
"gunk" growth like you mentioned.  We perform through wafer etch frequently
without such problem.  Hope this helps.

Best regards,

At 8:25 AM +0900 8/12/97, David T. Read wrote:
> ...
> Any advice as to what might be stopping the etch, how to keep the etch
> going, how to avoid mysterious passivation layers or reactions, what kind of
> oil to used in the mechanical pump, what kind of trap to use for the pump
> oil vapor, etc. would be appreciated.
> ...

_____________________________________________________________________
  _/    _/  _/_/_/_/   _/    Risaku Toda (Visiting from Ford Motor)
 _/    _/  _/     _/  _/        mailto:toda@cc.mech.tohoku.ac.jp
_/    _/  _/_/_/_/   _/        http://vbl.mech.tohoku.ac.jp/toda/
 _/ _/   _/     _/  _/
  _/    _/_/_/_/   _/_/_/_/                  Phone: +81-22-217-6256
Venture Business Laboratory, Tohoku Univ.    Fax:   +81-22-217-6259
_____________________________________________________________________