Abstract: A semiconductor component having a control structure for modulating the conductivity of a channel region wherein a small-area gate electrode of the proposed component covers the substrate only over a length L.sub.gd .apprxeq.L.sub.dep (L.sub.dep :=width of the space-charge zone in the substrate). An auxiliary electrode conductively connected to the source metallization and extending up to the edge of the symmetry unit is embedded in the gate oxide and is arranged spaced from the gate electrode. It sees to a comparatively uniform field distribution in the edge region of the gate electrode and thus prevents the electrical field strength in the semiconductor from reaching the critical value of approximately 10.sup.5 V/cm that triggers surge ionization.