[labnetwork] Oxidation of Si wafers with DRIE passivation polymer

[Lian, Yaguang]

Aaron,

This is a common process used to remove Teflon film and scallop from silicon after Bosch process. The Teflon film (F-C) is very hard to remove by O2 plasma. It cannot contaminate the tube. Carbon has chemical reaction with O2 to become CO2, it is gas. Fluorine is also gas. Both of them easily escape from the tube and cannot contaminate it. One more thing, we use HF to clean the tube. So I think it should be fine to use wet oxidation on Bosch silicon wafer.

Thanks,

Yaguang Lian
Research Engineer
2306 Micro and Nanotechnology Laboratory
University of Illinois at Urbana-Champaign
208 N. Wright St.
Urbana, IL 61801
Phone: 217-333-8051
Email: yglian at illinois.edu


From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Aaron Hryciw
Sent: 2016年8月3日 13:34
To: labnetwork at mtl.mit.edu
Subject: [labnetwork] Oxidation of Si wafers with DRIE passivation polymer

Dear colleagues,

Our facility recently installed a Tystar wet/dry oxidation tube, which has so far only been used to oxidise virgin Si wafers.  Recently, one of our users has requested to do a 400–1000 nm wet oxidation at 1100 °C on DRIE (Bosch) etched Si wafers which still have DRIE passivation polymer on them, for the dual purpose of removing the polymer and growing an oxide.

Given the tool's excellent performance so far, I am concerned with the possibility of contaminating the (atmospheric) tube as the polymer is burned off, adversely affecting subsequent processes.  My priority is to protect the integrity of the tool, but I also do not want to be needlessly restrictive if the presence of the polymer does not in fact pose any problem.  We are a multi-user facility, with academic and industrial users who primarily do MEMS and microfluidics work (i.e., no CMOS processing).

My initial thought would be to have this user remove the polymer first using a dry etch (O₂ plasma), only oxidising the wafers once it has been verified that the polymer is no longer present.

Any advice on this matter would be greatly appreciated.  Many thanks.

Cheers,

  – Aaron Hryciw




Aaron Hryciw, PhD, PEng

Fabrication Group Manager

University of Alberta - nanoFAB

W1-060 ECERF Building

9107 - 116 Street

Edmonton, Alberta

Canada T6G 2V4 Ph: 780-940-7938
www.nanofab.ualberta.ca<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.nanofab.ualberta.ca_&d=CwMFaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=e6po9udHSP-lsmrp548phJCJ6oxhBgeSbEZVeUn2v4Q&m=4Pudy5Ng9vOv9xxQMLxhixaa0fLs1myqVnTcC_hqrfU&s=qIbV9dCRTH8cbAanBngGK1nVhsCV7R7DG0hFpd9lJAg&e=>
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