Advances in foundry SiGe HBT BiCMOS processes through modeling and device scaling for ultra-high speed applications

Abstract

A new generation of Tower Semiconductor's SBC18 SiGe BiCMOS process family is introduced, SBC18H5, that features a baseline high-speed SiGe HBT with a peak f <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</inf> of 285 GHz and a peak f <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">MAX</inf> of 310 GHz. The process enhancements necessary to improve the HBT from the previous technology node are described as well as the accompanying mm-wave components that are complementary for front-end module design. A detailed TCAD analysis of the 1D vertical profile highlights additional opportunities to enhance the high-frequency performance of the SiGe HBTs without altering the existing integration. Base epitaxial experimentation based on these simulated changes results in increasing the f <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</inf> to 330 GHz and the f <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">MAX</inf> to 345 GHz. This process enhancement has been released as a stand-alone process, SBC18EH5, which combines the core component offering of SBC18H5 with the vertical profile optimized SiGe HBTs. Pushing the limits of lateral scaling based on extended 200 mm wafer lithography capability, a measured f <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</inf> /f <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">MAX</inf> of 350/500 GHz is achieved and will be released as a new stand-alone sixth generation process named SBC18H6.