The main objective of this Phase I SBIR is to develop a hermetic like protective coating which will not degrade performance of millimeter wave ICs. In Phase I, VT Silicon, Inc will collaborate with the Georgia Institute of Technology to demonstrate a low-cost, environmentally rugged coating on a custom designed millimeter wave (MMW) SiGe (Silicon Germanium) power amplifier (PA) IC. In Phase I, an innovative coating concept, the chemical modification of polymers, along with other coating concepts involving low stress polymer systems and polyimides will be evaluated. In order to have applicability to a wide variety of semiconductors such as GaAs, InP, and GaN, the compatibility of passivation layers with air bridges will be a key criteria in the choice a successful coating. The MMW SiGe PA IC will be fabricated in a commercial SiGe BiCMOS (Bipolar and CMOS devices) IC process with operation in the Ku band. The MMW SiGe PA IC with the deposited coating layer will be subjected to HAST and temperature cycling (-55C to 125C). The environmentally stressed MMW SiGe PA ICs will be tested to 40 GHz and the best coating layer will be selected. Manufacturability will be addressed with collaboration with semiconductor IC manufacturers.
