Mike, you need to use a columnated UV light source.

al

On Mon, 4 Feb 2002, Michael Roper wrote:

> Hello all,
>
> I am trying to etch glass using photolithography/wet etching techniques,
> but I have made an observation during my lithography steps. I use a
> photomask with various horizontal and vertical lines (all 5 um in width),
> after exposing the photoresist (AZ1520) to UV light, developer, and
> finally Cr etch, I have noticed that the horizontal lines are ~twice as
> wide as the vertical lines.  Interestingly, by keeping the mask in the
> same orientation to the glass, but moving the UV box 90 degrees, the
> vertical lines then become ~twice as big as the horizontal lines.
>
> I was wondering if this was a common occurence and if there is a simple
> solution....thought about spinning the photomask and glass or the UV
light
> as the glass was being exposed, but just curious if there was a simpler
> solution?  Thanks in advance to any help you can give.
>
> Mike
>
>
> Michael Roper
> University of Florida
> Chemistry Department
> 352-846-0838






Avi Laker
Teccor Electronics
972 756 8237   Office
214 439 6770   Pager