Abstract
Because of a higher permittivity than Al 2 O 3 , a large conduction band offset and high thermal stability, a thin amorphous Yb 2 O 3 layer was integrated with a ZrTiO 4 film as the gate stack for advanced Si MOS devices. With 800 °C annealing, the ZrTiO 4 film can be crystallized in orthorhombic phase with permittivity of 45.9 and a gate stack with equivalent oxide thickness of 0.86 nm can be achieved. This crystalline ZrTiO 4 Yb 2 O 3 gate stack demonstrates negligible frequency dispersion in capacitance, low interface trap density of 1.86 × 10 -11 cm -2 eV -1 , leakage current of 6.7 × 10 -6 Acm 2 at gate bias of flatband voltage (V FB ) -1 V , and high extrapolated 10-year lifetime operating voltage of-2.9 V. These promising electrical characteristics suggest that the crystalline ZrTiO 4 Yb 2 O 3 gate stack holds great potential to be applied to aggressively scaled CMOS technology. © 2012 IEEE.