Effect of Trap Profile on Device Characteristics of Metal–Oxide–Semiconductor Field Effect Transistors with Hafnium-Based Dielectrics

Abstract

The trap properties and performance of metal–oxide–semiconductor field effect transistors (MOSFETs) with either a HfSiO or HfO2 dielectric were determined using single-pulse Id–Vg and charge pumping measurements. The HfSiO dielectric shows a lower bulk trap density and a lower interface trap density than the HfO2 dielectric. Particularly, the trap depth profile as a function of distance from the Si/SiOx interface, which is obtained using frequency-dependent charge pumping measurements, shows a marked reduction in trap density in the HfSiO dielectric, unlike in the HfO2 dielectric. This significant reduction in trap density close to the Si/SiOx interface can contribute to the improvement in the carrier mobility of MOSFETs with a HfSiO dielectric.