SiGe heterojunction vertical p-type metal–oxide–semiconductor field-effect transistors with Si cap

Abstract

SiGe source heterojunction p-type metal–oxide–semiconductor field-effect transistors (p-MOSFETs) have been used before to suppress the short channel effect for sub-100 nm devices. While the leakage is reduced, the drive current is also reduced due to the heterojunction. In this letter, we discuss a SiGe source heterojunction vertical p-MOSFET with a few nanometers thick Si cap. With this device structure, the absence of the heterojunction-induced potential barrier right below the oxide interface improves the drive current substantially while the drain induced barrier lowering (DIBL) effect and floating body effect are still suppressed. The electrical characterization of the device shows it exhibits higher drive current and less DIBL compared with a Si control device.