[labnetwork] Filtering Setup and Documentation Request for Technics Planar Etch II Plasma Etcher

[Paolini, Steven]

Stefan,
   Where is CO being generated? CF4 and O2 are widely used and are not necessary to abate in most localities (check yours) In most applications, general exhaust will suffice for the pump effluent. If you are processing something that will form or release CO, no type of filter that I know of will trap it, it must be mitigated downstream of the pump in compliance to your lab safety folks and local codes.
What concerns me is that you MAY have a pump that uses hydrocarbon oil and that is a potential time bomb(literally) for any system running O2, you just can't and shouldn't do it. You can send the pump to a reputable rebuilder and they can clean it and prep it for inert oil such as Krytox or Fomblin which can be used with O2 service. Most dry pumps will suffice as well.
I don't know where you can get manuals for that system but I can tell you that they are very simple and I have repaired dozens of them. If there is a particular question on this unit, I would be happy to help you with it.

Steve Paolini
Equipment Dood
Harvard University Center for Nanoscale Systems
spaolini at cns.fas.harvard.edu


-----Original Message-----
From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Stefan Schoenleitner
Sent: Wednesday, August 06, 2014 3:24 PM
To: Labnetwork Mailing List
Subject: [labnetwork] Filtering Setup and Documentation Request for Technics Planar Etch II Plasma Etcher

Hello,

we recently acquired an old Plasma Etcher with a 750W 13.56 MHz RF plasma generator (Technics Planar Etch II, similar to the unit here:
http://www.cleanroom.byu.edu/pe2.phtml).

We are planning to use the unit with CF4 and O2 gas as well as N2 as vent gas. Our main application would be IC (integrated circuit) processing such as delayering or pre-processing for SEM analysis.

In order to get the system up and running, it would be helpful to receive operating and technical manuals for the system.
While we already have the unit's setup and operating manual, we are wondering if anyone has the following and could send it to us:

        * Schematic, model 750 plasma generator, d-3100-041
        * schematic, planaretch II system, c-3100-038
        * drawing, reference assembly, d-3100-049
        * drawing, p.c. board assembly, c-3100-048

In addition, we would like to know more about usable and practically safe vacuum and exhaust setups.
We currently have an Alcatel 2012A rotary vane vacuum pump that is not chemically resistant.
In order to filter out corrosive and/or poisonous gases such as CO, we would like to use an inlet trap as well as an oil mist and exhaust filter. After that, the exhaust should be vented to the outside of the building without further processing.

For the traps/filters, activated aluminia as well as activated charcoal filter media are available.

Examples:
http://www.pchemlabs.com/subcatagoryb.asp?pid=Replaceable-Element-Traps,-Plastic

Which filter media do you suggest for our application ?

Activated aluminia seems to work well with fluorides and appears to be widely used for plasma etching systems.
However, at the same time, both filter media do not seem to work well for filtering CO exhaust gas.

Another questions concerns storage of the inline trap.
If we don't use the devices that need vacuum pumps, we typically turn them off.
However, for the inlet traps this would mean that water and possibly a bit of dust could get into the inlet trap and, as a result, the filter media (i.e. activated aluminia) would get slightly moist.
Is that a problem ?
Should we store the inlet trap in vacuum, for instance by adding vacuum valves before and after the trap so that we can store it under vacuum (at least as long as the valves can hold the vacuum) ?


Thank you and best Regards,
Stefan

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