Negative Bias Temperature Instability in p-FinFETs With 45 $^{\circ}$ Substrate Rotation

Negative bias temperature instability (NBTI) reliability in p-FinFET devices is studied with respect to the silicon substrate orientation. Interface trap density Nit is lower in the 45° rotated devices compared with the 0° rotated devices because of lower density of Si dangling bond at the (100) side walls than the (110) side walls. This improves NBTI reliability in the 45° rotated FinFET devices. Furthermore, we demonstrate that the lower inversion charge density Ninv-exhibited when transitioning from planar to FinFET architecture at 45° rotation-plays an important role in the whole NBTI degradation. NBTI clearly improves in the 45° rotated FinFET devices compared with the planarlike device because of the lower Ninv. Leakage current density analysis is shown as an experimental proof, in addition to simulation results of Cho et al.