I usually use a low deposition rate, around 0.5 A/s, which normally gives a very flat surface and doesn't heat up the sample that much. Hope this helps.

Thank you, Dejan. I was also using 0.5 A/s.  Recently, Zhong et al. show that high purity Pd and evaporation at very low base pressures ( 10^-8 Torr) improve contact resistance. Therefore, I was thinking to try 1A/s or higher in order to deposit more pure Pd contacts. 

Article is attached.