Dear anonymous mems-talk member

without knowing any details of your photolithography process, it is
difficult to give specific advices. However, you should consider the
exposure dose as a parameter to adjust. Keep in mind that he surface of your
substrate may influence the optimum exposure dose. Resist on sputtered gold
needs more light compared to the same resist on bare silicon. The bake
condition you mentioned seems to be OK for a standard 1um thick positive
type photoresist.

Frank.