ALD HfO2/Ge wet etch at wbgen

Aryan Hazeghi hazeghi at
Mon Sep 12 12:15:57 PDT 2011

Hi Mary,

I'm sorry for the confusion, I mean wbgeneral. I need etching on the bench top just using the standard exhaust system and clean containers, no need to be connected to a load lock for my purpose.
Peter provided me with the info for the containers that I have to use and the draining.

Thanks all,

----- Original Message -----
From: "Mary Tang" <mtang at>
To: "Aryan Hazeghi" <hazeghi at>
Cc: specmat at, "Peter Griffin" <griffin at>, "Uli Thumser" <uli at>
Sent: Monday, September 12, 2011 12:02:39 PM
Subject: Re: ALD HfO2/Ge  wet etch at wbgen

Hi again --

Sorry, now I'm really reading your paper -- did you want to etch in an 
Ar or N2 environment??


On 9/12/2011 11:20 AM, Mary Tang wrote:
> Hi Aryan --
> I take it you really mean wbgeneral as opposed to wbgen2?  If so, 
> wbgeneral should be fine.  You will need to make sure your labware is 
> clean if you want your samples to remain clean.
> If you mean wbgen2, then I think we have to clarify what qualifies as 
> clean on this bench, since I don't believe Hf has been used on this 
> before.
> Please confirm which bench.
> Thanks,
> Mary
> On 9/9/2011 6:00 PM, Aryan Hazeghi wrote:
>> Hello,
>> I would like to wet etch HfO2 (ALD in Fiji-L clean chamber) /Ge at 
>> wbgen.
>> I will be using 50:1 DI:HF (please see the attached paper as one 
>> example.)
>> The reason I am choosing wet etch is because this is a thin film 
>> (50-70A)
>> functioning as gate oxide. The purpose of my research is to study the
>> interface and bulk properties modification of this film when exposed 
>> to a
>> low temperature, high radical density plasma at low power (TEL SPA.) 
>> Hence
>> the film need be preserved as much as possible and not exposed to other
>> plasma that might interfere with analysis of the effects of the TEL SPA
>> plasma. My feature size is ~1e2 um and not critical. I have not found a
>> labmember using HfO2/Ge wet etch at this wetbench so I would like to
>> confirm with specmat. I would like to know what draining procedure I
>> should follow.
>> Thank you,
>> Best,
>> Aryan
>> Aryan Hazeghi
>> Stanford Nanofabrication Facility
>> 304X Paul G. Allen
>> 420 Via Palou Mall
>> Stanford, CA 94305
>> 650-391-6509

Mary X. Tang, Ph.D.
Stanford Nanofabrication Facility
Paul G. Allen Room 136, Mail Code 4070
Stanford, CA  94305
mtang at

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