Hi Brad/Bill,

      I am totally intrigued by your suggestions.  How does plasma cleaning
help development?  Does it reverse the cross-linking that occurs?  Again,
our aim was to re-expose used resist and strip it off by development.  The
issue is that a top layer of that resist has been cross-linked (based on
development behavior) and in some instances, leave residue on the wafer.

Your thoughts are appreciated.


Brad Cantos   writes:

Have you tried doing a brief descum or surface plasma etch prior to
developing?  In the past when I used an iodine solution to etch
electroplated gold this usually helped.

Brad Cantos


On 9/2/08 3:44 PM, "rmartin@systron.com"  wrote:

>       I did some research on positive resist development but could not find
> any literature that shows what the development mechanism is of the
> indene-carboxylic acid photoproduct.  Am I to assume that it's a straight
> redox reaction (we use NaOH for our developer) producing a soluble salt
> by-product and water?
>
>       On a related note, I am trying to develop a flood expose and develop
> strip system to remove photoresist (using a mercury arc lamp as an exposure
> source and our current developer to strip).  It worked well in the initial
> stages, but now we are getting some residue which seems to be a result of
> the photoresist being affected by other wet processes involving
> permanganate and/or iodine.  Would increasing NaOH concenration help
> dissolve the resist?  Your thoughts are appreciated.