SOI technology pushes the limits of CMOS for RF applications

This last decade Silicon-on-Insulator (SOI) MOSFET technology has demonstrated its potentialities for high frequency commercial applications pushing the limits of CMOS technology. Thanks to the thinning down of the silicon channel, SOI MOSFETs operate in fully depleted regime and short channel effects are under controlled. Besides the gate length downscaling, strain channel engineering is introduced to achieve cutoff frequencies larger than 300 GHz. SOI also presents the major advantage of providing high resistivity substrate capabilities, leading to substantially reduced substrate RF losses, crosstalk and non-linearity. High Resistivity (HR) SOI CMOS is commonly foreseen as the most promising technology for radio frequency integrated circuits and mixed signal applications. Based on several experimental results, the interest, limitations but also possible future improvements of SOI MOS technology are presented.