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 ch annel length imposes severe constraints on the doping profile. MBE gro wth provided a steepness of 10 nm/dec for boron and 2 nm/dec for antim ony. The sharpness of the doping profile was sustained throughout the process by keeping all process temperatures below 700-degrees-C. The h igh crystal quality and the well-defined doping profile was verified b y the good performance of a triangular barrier diode. A vertical n-MOS FET 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.