Solid liquid interdiffusion bonding near room temperature for micro devices

The development of gallium/gold and gallium/copper alloy formation near the melting point of gallium is carried out for the application of metal interdiffusion bonding of semiconductors using operation temperatures near room temperature.

Therefore an electrodeposition process has been developed to uniformly coat semiconductor surfaces with gallium. The process is characterized by the intermetallic composition of the resulting alloys and extensive research of the shear strength, electrical conductivity and hermeticity. All these characteristic values have been optimized. Micro structural analysis has been performed at the interfaces obtained at different process temperatures. The output of the research is a unique thin film liquid metal based bonding process for MEMS working near room temperature.