[labnetwork] HBr and Cl2 mixing gases

[Lavendra Yadav Mandyam]

Hi Mingwei,

We have the similar setup here at Stanford, with Cl2, BCl3 and HBr.
This tool is primarily dedicated to III-V etching, as well as Poly-Si etching using HBr and Cl₂.

  1.  Yes, you can. HBr offers excellent selectivity with oxide which making it less ideal for breaking native oxide. HBr alone also has slower etch rates compared to F or Cl2 chemistries. However, adding Cl₂ to HBr during the breakthrough step can effectively break the oxide layer and increase the etch rate. You can switch to HBr alone in Over etch step to precisely land on SiO₂. (you can substitute the Cl2 and HBr with C2F6/CF4/CHF3 in the breakthrough step)
  2.  We routinely mix these chemistries, and both III-V and Si etching remain stable, provided chamber cleaning and seasoning are performed regularly.
  3.  Si byproducts are fairly volatile, but we clean the chamber with SF6/O2 to manage the chamber effectively.
Let me know if you have any questions.

Best,
Lavendra Mandyam
Process Engineer – Dry Etching
Stanford Nanofabrication Facility
Paul G. Allen Building
420 Via Palou Mall
Stanford, CA 94305
Phone: (650) 498-1304
https://snf.stanford.edu/
lavendra at stanford.edu<mailto:lavendra at stanford.edu>



---------- Forwarded message ---------
From: MINGWEI LIN < >
Date: Tue, Aug 27, 2024 at 1:08 PM
Subject: [labnetwork] HBr and Cl2 mixing gases
To: labnetwork at mtl.mit.edu<mailto:labnetwork at mtl.mit.edu> < >

Hi, Everyone:
We are going to purchase a new metal etcher with Cl-based and HBr gases. Can anyone share the experience of HBr and Cl-based mixing gases for the etcher?
1. Can the HBr and Cl2 mixing gases be used together for the Si/Poly Si etch? If Cl2 was used first followed by HBr, would any cleaning be necessary in between?
2. Does anyone know about any impact on III-V materials (GaN for example) etch or device performance if HBr and Cl2/BCl3 are used in the chamber?
3. If there is cross contamination issue about the mixing gases, what about the cleaning criteria if we switch HBr and Cl-based gases back and forth? Any better way for the tool management?
Thanks/regards,

MINGWEI LIN, PhD
Process Engineer
Nanoscale Fabrication Center
University of Wisconsin-Madison

_______________________________________________
labnetwork mailing list
labnetwork at mtl.mit.edu<mailto:labnetwork at mtl.mit.edu>
https://mtl.mit.edu/mailman/listinfo.cgi/labnetwork
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20240827/ad19d171/attachment.html>