I've experienced similar issues using lor 3a which was way past it's shelf life.
In the end, a fresh bottle solved all the issues.

Gabriel

> On Jul 14, 2015, at 3:41 PM, Joshua Wells  wrote:
>
> Thanks for the input. Unfortunately we are limited to using microdev
> developer for this process due to material compatibility. We are also not
> using an automated developing system. I have done quite a few experiments
> using different bake times and temperatures and have also found that higher
> temperatures at longer times works best. The biggest issue we are seeing is
> small LOR dots in the exposed area that will not develop away.  They appear
> random and vary in thickness. Some of the features are smaller and these
> "dots" cause the device to be rendered unusable after metallization.
>
> Joshua
>
> On Tue, Jul 14, 2015 at 12:52 AM, André Bödecker <
> aboedecker@imsas.uni-bremen.de> wrote:
>
>> We had also problems while using an automatic developing device. The
>> undercut depends among other things on the abrasive effect of the spraying
>> direction of the developer tool. We made better experience with manual
>> developing in a petri dish and always using fresh developer.
>>
>> André
>>
>> -----Ursprüngliche Nachricht-----
>> Von: mems-talk-bounces+aboedecker=imsas.uni-bremen.de@memsnet.org
>> [mailto:mems-talk-bounces+aboedecker=imsas.uni-bremen.de@memsnet.org] Im
>> Auftrag von Joshua Wells
>> Gesendet: Freitag, 10. Juli 2015 13:43
>> An: mems-talk@memsnet.org
>> Betreff: [mems-talk] Liftoff Process Using LOR 10B and 1800 Series Resist
>>
>> I am trying to develop a repeatable liftoff process using LOR10B and an
>> 1800 series positive resist for use with 1:1 microdev developer (necessary
>> for material compatibility). The trouble arises in the repeatability of the
>> process. Time of development varies significantly between runs with no
>> process parameters changing yielding far too much undercut for our
>> application. We have the LOR thinner and have by trying to work with that
>> as
>> well as full thickness LOR.
>>
>> Does anyone have a repeatable process or suggestions?
>>
>>
>> Joshua
>> _______________________________________________
>> Hosted by the MEMS and Nanotechnology Exchange, the country's leading
>> provider of MEMS and Nanotechnology design and fabrication services.
>> Visit us at http://www.mems-exchange.org
>>
>> Want to advertise to this community?  See http://www.memsnet.org
>>
>> To unsubscribe:
>> http://mail.mems-exchange.org/mailman/listinfo/mems-talk
>>
>> _______________________________________________
>> Hosted by the MEMS and Nanotechnology Exchange, the country's leading
>> provider of MEMS and Nanotechnology design and fabrication services.
>> Visit us at http://www.mems-exchange.org
>>
>> Want to advertise to this community?  See http://www.memsnet.org
>>
>> To unsubscribe:
>> http://mail.mems-exchange.org/mailman/listinfo/mems-talk
> _______________________________________________
> Hosted by the MEMS and Nanotechnology Exchange, the country's leading
> provider of MEMS and Nanotechnology design and fabrication services.
> Visit us at http://www.mems-exchange.org
>
> Want to advertise to this community?  See http://www.memsnet.org
>
> To unsubscribe:
> http://mail.mems-exchange.org/mailman/listinfo/mems-talk
_______________________________________________
Hosted by the MEMS and Nanotechnology Exchange, the country's leading
provider of MEMS and Nanotechnology design and fabrication services.
Visit us at http://www.mems-exchange.org

Want to advertise to this community?  See http://www.memsnet.org

To unsubscribe:
http://mail.mems-exchange.org/mailman/listinfo/mems-talk