[labnetwork] Cryo Si Etching

[Luciani, Vincent (Fed)]

Hello Bob,
We have a Cryogenic ICP system.  There are folks in this group that can give a much more detailed answer than I can but from the NanoFab Manager's view point I can state the following:

The most obvious is that it enables very high power density and other more exotic etches.  You can also get vertical sidewalls in thick dielectrics which has been very useful to our friends near us at the NIH.  It is a nice RIE research feature and 

What I don't like:
Because of the hardware design that provides the cooling, it is much more finicky than a basic flat platen or electrostatic chuck.  Keeping the helium leak-rate from the backside low requires time and effort from the equipment engineers.  Even for room temperature etches, the cryogenic chuck adds more failure modes in getting any wafer in then out.  It requires frequent staff intervention to help users with wafer transport and positioning problems.  Non-flat wafers present a significant problem.

It is a matter of how important it is for your users to have the process capability vs your ability to maintain uptime on the tool to everyone's satisfaction.  I will gladly connect you to our RIE engineer and/or our Equipment Engineer if you like.

Vincent K. Luciani
Center for Nanoscale Science and Technology
National Institute of Standards and Technology
100 Bureau Drive, Stop 6201
Gaithersburg, MD  20899-6201



-----Original Message-----
From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Geil, Bob
Sent: Thursday, May 10, 2018 4:21 PM
To: labnetwork at mtl.mit.edu
Subject: [labnetwork] Cryo Si Etching

I'm wondering if anyone has worked with Cryogenic ICP etch systems for Si processing.  Oxford Instruments is the only vendor I could find that manufactures these systems.  There also seems to be only a couple of university micro/nanofab facilities with such a system: Georgia Tech and U. Michigan (I'm sure I missed a few others...)   So, my questions are:  does anyone know of other vendors that manufacture cryo ICP etch systems, and is there a particular reason these systems seen to be unpopular?

Best regards,
  Bob Geil

Bob Geil, PhD
Cleanroom Manager, CHANL
Chapel Hill Analytical and Nanofabrication Laboratory Department of Applied Physical Sciences University of North Carolina
223 Chapman Hall, CB# 3216
Chapel Hill, NC 27599

Phone: (919) 843-6555