I think aluminum films inevitably gets rough as they grow thicker because of the
way they grow. You might want to look up Al-Si(1%) targets.

Just a thought.

Matthieu Nannini
McGill Nanotools

> Message: 1
> Date: Wed, 14 Dec 2011 13:01:18 -0500
> From: "Li. Zhang" 
>
> Hi everyone,
>
> I obtained a surface roughness of <1nm (RMS value) using for 10nm thick
> aluminum film using heat evaporation process. However, as I increased the
> thickness to ~200nm, the surface roughness degraded to >4.5nm. I know
> sputtered aluminum film may have better surface quality, but am not sure
> about the its surface roughness range for 50nm and 200nm-thick aluminum
> films. Any idea is appreciated!
>
> Thanks,
> Li