Characterization of oxide traps in 28nm n-type metal-oxide-semiconductor field-effect transistors with different uniaxial tensile stresses utilizing random telegraph noise

In this study, the effect of uniaxial tensile on the SiO2/Si interface of the 28nm n-type metal-oxide-semiconductor field-effect transistors (nMOSFETs) has been investigated. nMOSFETs were fabricated with different thicknesses of the stress-memorization technique (SMT) films to further increase channel stress because the SMT films can provide a higher uniaxial tensile to the channel. Trap behaviors such as activation energy and depth were characterized on the basis of drain current random telegraph noise (RTN). By RTN analyses, we found that the trap energy level is closer to the channel conduction band as the tensile strain in the channel increases higher, resulting in the trap being located close to the SiO2/Si interface.