Re: Patterning using photolithography

I'll chime in with a couple of thoughts also:

1) bake temp - 115ºC/60 seconds seems kind of high to me, I'd probably drop
it back to 100ºC.
2) Exposure dose - increasing dose should get you to clear - IIRC, S1813 was
fairly slow, (I worked at Shipley in the early 90's and tested this resist
frequently) show bumping the dose should help.
3) Acetone works well only prior to expose/develop. Once a resist has been
developed, Acetone has a hard time cutting the polymer matrix. You should
consider the NMP or EBR style strippers.

Craig

in article [EMAIL PROTECTED], John Damiano at
[EMAIL PROTECTED] wrote on 10/9/03 2:20 PM:

> Supriya,
> 
> 1.  I agree with the previous posters re: increasing the exposure
> time, also verify that your developer is fresh.
> 
> 2.  In addition to the plasma / piranha solutions, do you have access
> to Microposit 1650 resist stripper?  10 minutes in 1650 should remove
> your resist.  Another possibility is a product called "Nano EBR" -
> basically edge bead remover - which effectively and quickly strips
> resist in my experience.  Both of these will work better than acetone
> and are safer than piranha.  Good luck.
> 
> John Damiano
> Protochips Inc.
> 
> 
> "Dwayne" <u m c h r u s 1 @ c c . u m a n i t o b a . c a> wrote in message
> news:<[EMAIL PROTECTED]>...
>> "Alex Kaiser" <[EMAIL PROTECTED]> wrote in message
>> news:[EMAIL PROTECTED]
>>> Hi!
>>> 
>>> 1. increasing the exposure time may help
>>> 
>>> 2. for removal of resist you may also use 1-methyl-2pyrrolidone, at high
>>> temperature over 100 degrees.
>>>   another possibility is to use a mixture of 1 part of H2O2 and 2 parts of
>>> H2SO4 if your substrate allows this treatment. But be careful with this.
>>> 
>> 1. Agreed, as photoresist ages the exposure time need to be increased.  Four
>> seconds seems to short, but then again I use different resists.
>> 
>> 2. Pour 1 part (by volume) H2O2 slowly into 3 parts H2SO4 into a glass
>> beaker (the solution will heat up as you add the Hydrogen Peroxide).  Then
>> place one wafer at a time slowly into the mixture.  This etchant is called a
>> Piranha and it's called that for a good reason (it eats anything organic
>> including people). Be very careful, it reacts violently and can potentially
>> exploded, spraying hot sulfuric acid everywhere. Make sure to where an acid
>> gown and face shield and have a buddy standing by.
>> 
>> Dwayne