To disclose a field effect transistor having an ultra-short channel length and the method of fabricating the same.

The ultra-short channel field effect transistor includes: a three-dimentional structure silicon-wire channel region; a source/drain junction formed of silicon conductive layers formed on both sides of the silicon-wire channel region; a gate electrode formed on the upper part of the silicon-wire channel region through a gate insulation film having a high dielectric constant therebetween; and source/drain electrodes connected to the source/drain junction. In the present invention, the stereostructural silicon-wire channel region can be formed to have a trapezoidal or trigonal profile through the utilization of the difference in an etching speed depending on a surface orientation of silicon, and the source/drain junction can be formed through the solid-state diffusion method.