I am trying to make an electrical connection to a silicon wafer using a wire (approx 32AWG).
I find that conventional lead/tin (60/40, no flux) solder cannot adhere well to the silicon wafer, since the solder will simply fall off the wafer after cooling (same to both polished and unpolished side of wafer).
I tried depositing a layer of aluminium (1µm thick, by DC sputtering) on the silicon with the guess that solder and silicon were incompatible. However, the adhesion between the sputtered aluminium layer and the solder was still very weak.
What can I do to the silicon wafer so that I can make an electrical connection to it?