Vertical Si-Metal-Oxide-Semiconductor Field Effect Transistors with Channel Lengths of 50 nm by Molecular Beam Epitaxy

The growth conditions in molecular beam epitaxy (MBE) were studied for the fabrication of vertical Si-metal-oxide-semiconductor field effect transistors (MOSFET) with channel lengths down to 50 nm. The short channel length imposes severe constraints on the doping profile. MBE growth provided a steepness of 10 nm/dec for boron and 2 nm/dec for antimony. The sharpness of the doping profile was sustained throughout the process by keeping all process temperatures below 700° C. The high crystal quality and the well-defined doping profile was verified by the good performance of a triangular barrier diode. A vertical n-MOSFET with an estimated channel length of 50 nm was grown. The drain and gate characteristics were discussed for a source drain voltage regime from U _sd=0 V to 1 V.