Device having a titanium-alloyed surface
Disclosed is a device that includes a crystalline substrate and a patterned aluminum-based material layer disposed onto the crystalline substrate. The patterned aluminum-based material layer has a titanium-alloyed surface. A titanium-based material layer is disposed over select portions of the titanium-alloyed surface. In an exemplary embodiment, the patterned aluminum-based material layer forms a pair of interdigitated transducers to provide a surface wave acoustic (SAW) device. The SAW device of the present disclosure is usable to realize SAW-based filters for wireless communication equipment.
1. A method of fabricating a device comprising:
disposing a patterned aluminum-based material layer onto a crystalline substrate;
disposing a titanium-based material layer over the patterned aluminum-based material layer; and
etching away portions of the titanium-based material layer from portions of the patterned aluminum-based material layer to leave an exposed titanium-alloyed surface on the portions of the patterned aluminum-based material layer.
2. The method of fabricating the device of claim 1 wherein the patterned aluminum-based material layer forms a pair of interdigitated transducers to provide a surface wave acoustic device.
3. The method of fabricating a device of claim 2 further including disposing an under bump metallurgy layer comprising a metal directly in contact with the portions of the exposed titanium-alloyed surface.
4. The method of fabricating a device of claim 3 wherein contact resistivity between the under bump metallurgy layer metal and the exposed titanium-alloyed surface is in the range of 1×10-8 and 1×10−7 ohm/cm2.