AMD strictly moderated (AMD)

[kpf]

Chipguy

That being said, AMD probably has other reasons to use an
Al layer at 65 nm because this scaling effect will likely only
really start to bite at perhaps 32 nm and below.

Right you are. These reasons seem to be good enough to use Al in 45nm as well:

http://journal.mycom.co.jp/articles/2006/12/12/iedm1/

The intermediate (middle level) and global (upper) wires will still be copper because of lower RC delay and much better
ability to carry high current reliably.

Apparently not. I see it is in layer 1. Just curious, do they do this in 90nm as well? I am asking because I remember they had nasty problems in 130 bulk with copper damascene effects, maybe that's why they use Al nowadays?

K.