Monolithic microwave integrated circuit on high resistivity silicon

摘要

A silicon-based monolithic microwave integrated circuit architecture is described. This architecture, called MICROX TM , is a combination of silicon material growth and wafer processing technologies. A wafer is fabricated using a substrate of high resistivity silicon material. An insulating layer is formed in the wafer below the surface area of active silicon, preferably using the SIMOX process. A monolithic circuit is fabricated on the wafer. A ground plane electrode is formed on the back of the wafer. Direct current and rf capacitive losses under microstrip interconnections and transistor source and drain electrodes are thereby minimized. Reduction in the resistivity of the substrate material as a result of CMOS processing can be minimized by maintaining a shielding layer over the bottom surface of the wafer. Microstrip and airbridge connectors, salicide processing and nitride side wall spacing can be used to further enhance device performance. The resulting architecture is an alternative to gallium arsenide integrated circuits for microwave applications.