Hello kirt,

I am also trying to use HNA. I contacted with Shipley and they have
S1818 and S1827. Will they work as HNA mask and can you suggest a receipt?

>> I am trying to isotropically wet etch silicon using a
>> 126:60:5 HNO3:H20:NH4F
>> etchant (as described by Williams and Muller, J. of MEMS
>> 1996).  The etchant
>> appears to work well, but masks made of AZ5214 do not.  In less than
>> 15 minutes, the AZ5214 layer has visibly thinned and formed holes.
>>
>> Can anyone recommend a more durable mask (PR, metal, both or
>> otherwise) for this etchant?

kac> In my measurements with this etchant the photoresist etch rate was zero
kac> (or it might have even swelled slightly).
kac> Try OCG (formerly KTI) 820 or similar in this series of resists
kac> or
kac> Shipley Microposit 1822 or similar in this series.
kac> Silicon dioxide is slowly etched.
kac> Silicon nitride is barely etched.
kac> Titanium is etched.
kac> Chromium is not etched.

kac>         --Kirt Williams Agilent Technologies
kac> _______________________________________________
kac> [email protected] mailing list: to unsubscribe or change your list
kac> options, visit http://mail.mems-exchange.org/mailman/listinfo/mems-talk
kac> Hosted by the MEMS Exchange, providers of MEMS processing services.
kac> Visit us at http://www.mems-exchange.org/




Best regards,
 Weili                            mailto:[email protected]

----
Weili Liu
14-124 Engineering IV
Department of Mechanical and Aerospace Engineering
University of California-Los Angeles
420 Westwood Plaza, Los Angeles, CA90095
Tel: 310-825-7457
Fax: 310-206-2302