Wafer-Scale 3D Integration of Silicon-on-Insulator RF Amplifiers

RF amplifiers are demonstrated using a three- dimensional (3D) wafer-scale integration technology based on silicon-on-insulator (SOI) CMOS process. This new 3D implementation reduces the amplifier size and shortens interconnects for smaller loss and delay. In addition, 3D integration allows the stacking of wafers fabricated using different process technologies to optimize the overall circuit performance at the lowest cost. In RF amplifier examples, MOSFETs and passive components are placed on separate tiers to reduce the size. Measured amplifier performance agrees well with simulation and footprint reduction of approximately 40% comparing to conventional 2D layout can be achieved.