A comparison of floating-body potential in H-gate ultrathin gate oxide partially depleted SOI pMOS and nMOS devices based on 90-nm SOI CMOS process

Based on a 90-nm silicon-on-insulator (SOI) CMOS process, the floating-body potential of H-gate partially depleted SOI pMOS and nMOS devices with physical gate oxide of 14 Å is compared. For pMOS devices, because the conduction-band electron (ECB) tunneling barrier is lower (≅3.1 eV), the ECB direct-tunneling current from the n⁺ poly-gate beside the body terminal will contribute to a large amount of electron charges into the neutral region and dominate the floating-body potential under normal operations. Conversely, owing to the higher valence-band hole tunneling barrier (≅4.5 eV), the floating-body potential of nMOS devices is dominated by the band-to-band-tunneling mechanism at the drain-body junction, not the direct-tunneling mechanism.