Strained FDSOI CMOS technology scalability down to 2.5nm film thickness and 18nm gate length with a TiN/HfO2 gate stack

Scalability of both unstrained and strained FDSOI CMOSFETs is explored for the first time down to 2.5 nm film thickness and 18 nm gate length with HfO₂/TiN gate stack. Off-state currents in the pA/mum range are achieved for 18 nm short and 3.8nm thin MOSFETs thanks to outstanding electrostatic control: 67 mV/dec subthreshold swing and 75 mV/V DIBL. For such thin bodies, the buried oxide fringing field limitation on DIBL is experimentally evidenced and quantified for the first time. Furthermore, we demonstrate strain induced I_ON gain as high as 40% on the shortest transistors. An in-depth analysis of this gain as a function of the film thickness is carried out through mobility and ballisticity extractions.