US Patent 7936065 Semiconductor devices and method of manufacturing them

A semiconductor device is provided with a silicon substrate, with a surface for soldering the silicon substrate to a ceramic substrate, and an electrode making contact with the surface of the silicon substrate. The electrode comprises a first conductor layer, a second conductor layer, and a third conductor layer. The first conductor layer makes contact with the surface of the silicon substrate and includes aluminum and silicon. The second conductor layer makes contact with the first conductor layer and includes titanium. The third conductor layer is separated from the first conductor layer by the second conductor layer and includes nickel.