A novel tensile Si (n) and compressive SiGe (p) dual-channel CMOS FinFET co-integration scheme for 5nm logic applications and beyond

A novel tensile Si (tSi) and compressive SiGe (cSiGe) dual-channel FinFET CMOS co-integration scheme, aimed at logic applications for the 5nm technology node and beyond, is demonstrated for the first time, showing electrical performance benefits and excellent co-integration feasibility. A Strain-Relaxed SiGe Buffer (SRB) layer is introduced as buried stressor and successfully transfers up to ∼1 GPa uniaxial tensile and compressive stress to the Si/SiGe n-/p-channels simultaneously. As the result, both tSi and cSiGe devices show a 40% and 10% electron and hole mobility gain over unstrained Si, respectively. Through a novel gate stack solution including a common interfacial layer (IL), HK, and single metal gate for both n- and pFET, secured process margin for 5nm gate length, low interface trap density (Dit) for SiGe channel and threshold voltage (Vt) target for both the Si and SiGe device are successfully demonstrated. Lastly, reliability investigation shows that tSi and cSiGe, employing the newly developed common gate stack scheme, possess superior reliability characteristics compared with those of equivalent Si devices.