I know faster the Al deposition rate, the better reflectivity for the
mirror.

You are saying better uniformity and adhesion if evaporation is slow. What
is the rate are you talking about?

Do the above 2 comments contradict with each other?

-Andrew

> You could use E-Beam Evaporation and may also try a slow rate of
> evaporation
> for better uniformity and adhesion. We are able to deposit very thick
> layers
> of aluminum (usually around 6 micron) by E-Beam Evaporation. Good Luck!