Dear Michael,

I believe you can achieve thickness up to 70 um by using multiple spin
coating of AZ9260 . I have achieved an aspect ratio of 5 (12 um feature in
60 um thick film of AZ9260) and deposited copper in these molds.

at 1000 rpm, you get about 20-22 um thick layer. The important parameters
are prebake duration, exposure dose, development time.

For 60 um thick film, my parameters were:
1 spin: at 1000 rpm for 40 s, prebake at 110 degree for 1 min
2 spin:at 1000 rpm for 50 s, prebake at 110 degree for 80 s
3 spin: at 800 rpm for 60 s, prebake at 110 degree for 4 min

exposure energy 1800 mJ/cm2, development time about 5 min.

for brief details You can look at  Journal of Micromechanics and
Microengineering 17(5) 1078 (2007).

Hope it help you..

Thanks,
Pradeep

On Tue, Jun 3, 2008 at 4:26 PM, Haixin Zhu  wrote:

> Dear all,
>
> I am trying to produce 20um features using AZP4620, the thickness is
> required to be 38um, I tried double coating/triple coating with various
> spin speed and baking condition, and they did not work. Is there any one
> having this experience and advise me on the right direction?
>
> Appreciate the help
>
> Michael