Characterization of Oxide Tarps in 28 nm p-Type Metal--Oxide--Semiconductor Field-Effect Transistors with Tip-Shaped SiGe Source/Drain Based on Random Telegraph Noise

In this study, the impact of embedded tip-shaped SiGe in the source/drain (S/D) region on individual trap behavior such as activation energy and depth from the SiO2/Si interface of the 28 nm p-type metal–oxide–semiconductor field-effect transistors (pMOSFETs) has been investigated on the basis of drain current random telegraph noise (RTN). The purpose of implementing tip-shaped SiGe S/D is to further increase channel stress because it provides a closer proximity of embedded SiGe to the channel. By characterizing RTN, we found that the pMOSFETs underwent uniaxial compressive strain that was provided by tip-shaped SiGe S/D, and the trap energy level being close to the channel valence band resulted in the trap located close to the Si/SiO2 interface, as compared with the control device without embedded SiGe S/D.