A field effect transistor in which at least one vertically arranged
semiconductor column, with a diameter in the nanometer range, is located
between a source and a contact and has an annular surround of a gate
contact with retention of an insulation gap. A simplified production
method is disclosed and the transistor produced thus is embodied such
that the semiconductor columns are embedded in a first and a second
insulation layer, between which a metal layer, running to the outside as
a gate contact, is arranged, the ends of which, extending upwards through
the second insulation layer, are partly converted into an insulator, or
removed and replaced by an insulation material.