Experiment Characterization of Front and Back Interfaces Impact on Back Gate Modulation in UTBB-FDSOI MOSFETs

An analytical method considering the charge coupling effect in UTBB FDSOI device is proposed to extract trap densities at front and back interfaces. The back-gate modulation with the dependence of interface traps is investigated in the advanced UTBB FDSOI device stressed by hot carrier injection (HCI). The experimental results show that the initial back-interface states are more than that of the front interface. Both the trap densities of the front and back interfaces increase with longer HCI stress. Moreover, the HCI stress weakens back-biasing capability especially at the scenario of the high-performance application. Larger forward back bias leads to the more charged back-interface states, thereby reducing the modulation range of back biasing.