Pradeep,

The rate of deposition depends more on current density and temperature.
However, the shapes achieved by electrochemical deposition varies depending
on the features of photoresist mould. Due to current crowding effect
accompanied by local field variation within the opening you might experience
higher deposition at the corners compared to the middle of the vias.
Something like a U-shaped profile. You might have to consider that before
you start your deposition runs.

Regards,
Prasanna

On Fri, Jul 3, 2009 at 10:24 AM, Pradeep Dixit wrote:

> Hello All,
>
> I would like to check some thing with you.
>
> During through-resist electroplating, does metal deposition rate depend
> upon the opening dimension of features?
>
> I am trying to electroplating 8 um thick copper structures. resist mold is
> 12 um thick AZ9260. Seed layer is 30 nm TiW/ 300 nm Cu.
>
> features are circular vias and have relatively large variation in diameter.
> 20 um vias are besides 100 um vias and 500 um vias.
>
> Electroplating type: DC, 5 mA/cm2 current density
>
> I want to know in advance:
>
> will the electroplated thickness be same for all feautures (20 um, 100 um,
> and 500 um) ?
>
> OR
>
> 500 um diamter vias will be plated faster .
>
> Your opinion will be appreciated.
>
>
> Thanks,
> Pradeep

--
Thanks & Regards,
Prasanna Srinivasan