Flip-Chip Integration of III-V Chips on Wafer for mmW Applications

The process of integration multiple chips, fabricated on various semiconductor technologies, is a basic requirement in transforming the parameters of transistors and MMICs to a multifunctional system on a single substrate. Traditional methods of integration with bond wires transitions limits the available potential of state-of-art transistors and MMICs due to significant effect on frequency band and form-factor of the device. Using flip-chip approach with new types of interconnections, we were able to successfully integrate different semiconductor technologies at the wafer-level for enhanced RF performance. As an example, GaAs chip of coplanar line was integrated onto a Sapphire substrate to achieve enhanced RF performance. Two types of forming interconnection are used: Au-Au for connection by thermocompression method, and Au-Sn system for SLID bonding. We demonstrate technology and experimental results of these construction from DC to 50 GHz. Initial results of mechanical reliability were obtained.