GaAs MESFET and Si CMOS cointegration and circuit techniques

The cointegration of GaAs MESFET and Si CMOS circuits on a single chip has recently been achieved using GaAs-on-Si epitaxial growth techniques. The authors discuss the device and circuit aspects of GaAs/Si cointegration and describe some circuit techniques for monolithically interfacing between GaAs MESFET and Si CMOS circuits. The cointegration was realized in a planar structure appropriate for IC (integrated circuit) processing, which allows interconnection of the two types of circuits by conventional metal interconnects. Specifically, the process was demonstrated by fabricating composite ring oscillators consisting of GaAs MESFET BFL (buffered FET logic) inverters and Si CMOS inverters connected in a ring.<>