Hi Kishore.
Are you etching the SiO2 as a release or sacrificial layer.
In many cases when people are looking for selectivity to nitride they switch to
silicon as a release layer. KOH will etch poly-Si without attacking your nitride
or for a dry etch XeF2 shows a high selectivity to nitrides over Si (on order of
200:1 and higher). The other advantage of XeF2 is it is extremely selective to
everything else so you can use a very thin oxide layer or photo resist to
protect any Si you don't want etched.
Could you switch to Si as a release layer?
Regards
David Springer
XACTIX, Inc.
2403 Sidney, St.
Suite 265
Pittsburgh, PA 15203
412 381 3195
[email protected]
www.xactix.com
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>> Hi,
>> I was wondering if someone could point me towards an etchant that would
>> selectively etch SiO2, but not Nitride. I tried using BOE, but the
>> selectivity was pretty low.
>> Thanks,
>> Kishore
>> - --
>> __________________________________________________________________________
>> ____
>> Kishore Sundara-Rajan Dept. of Electrical Engineering
>> Graduate Research Assistant University of Washington
>> [email protected] Campus Stop 352500
>> Mobile : (206) 351-8101 Seattle WA 98105
>> Fax : (206) 632-3080 Office : (206) 221-6673
>> http://students.washington.edu/kishore www.kishore-sr.com
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