Helia offer sputtered and electron beam (or combination) metals for n-side contacts on up to 4” InP and GaAs wafers. Typically these use a thin bonding layer (nickel or titanium) a gold and germanium stack which is then alloyed by annealing at the eutectic point and then a solder attach – compatible platinum gold pair completes the growth. Variations are offered including palladium and various TCOs for vertical applications.
These are high-volume cost-effective processes for multi-wafer processing.
Helia have state-of-the-art supporting metrology for the electrical characterisation of these contacts.