Warren,  One way round this I have used is to get one or more
wafers fabricated with a blanket covering of the metal you are
interested in. In my case I had a 4" Si wafer with a layer of
SiO2 followed by Al1%Si for the bonding layer. The supplier then
diced the wafer and put the die into waffle pack. Using blanket
covering means that no expensive masks need to be made and