[labnetwork] Deep Reactive Ion Etch Problems

[Beall, James A. (Fed)]

When we see that it often means you are overdue for chamber cleaning and reconditioning.
For us (SPTS Pegasus 150 mm tool) that is a long O2 chamber clean with a wafer on the chuck) followed by running our standard Bosch process on bare silicon full wafers until they come out shiny.
If that fails then you need manual chamber wall clean (iso and scotchbrite) followed by the above.

Best of luck,

Jim
________________________________
From: labnetwork-bounces at mtl.mit.edu <labnetwork-bounces at mtl.mit.edu> on behalf of Pallavi Sharma <pnsharma at unm.edu>
Sent: Monday, July 27, 2020 10:02 AM
To: labnetwork at mtl.mit.edu <labnetwork at mtl.mit.edu>
Subject: [labnetwork] Deep Reactive Ion Etch Problems

Hello all,

I am having problem with anisotropic etching of silicon by Deep Reactive ion etch. Grass or black silicon is the issue all the time, attaching some of the SEM pictures of the sample. Every recipe I tried to fine tune result in grass formation, even as the process initiates in tool wafer surface starts to turn brown and ultimately black. I tried varying SF6 gas flow, Bias power, Substrate temperature but every time I see is highly dense grass with no clean surface.
Any help will be greatly appreciated.

Thank you,
Pallavi

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