High hole mobility of Al2O3 mosfets on dislocation free Ge-on-insulator wafers

Abstract

The much degraded mobility, high-kappa dielectric crystallization, and EOT reduction after processing are the primary limitations of high-kappa gate dielectric MOSFETs. We have fabricated the high-kappa Al2O3 MOSFET on Geon-Insulator to enhance the hole mobility. The measured hole mobility with 1.7 nm EOT is 73 cm(2)/Vs at E-eff of 1 MV/cm, which is 2.5 times and 1.3 times higher than and Al2O3/Si control devices and SiO2/Si universal mobility, respectively. In additional to good dielectric reliability, the low temperature process (less than or equal to500degreesC) can also avoid high-kappa dielectric crystallization and EOT reduction by O-2 or moisture penetration through high-kappa dielectric.