Patent ID: 6878993

Claim:
A trench junction field-effect transistor comprising: a semiconductor substrate doped with impurity of a first conductivity type, the substrate forming at least part of the drain of the transistor; an epitaxial layer grown over the substrate, the epitaxial layer being doped with impurity of the first conductivity type and having a doping concentration generally lower than the doping concentration of the substrate; at least two trenches formed in the epitaxial layer, the trenches defining a mesa; a source region located in the mesa at a surface of the epitaxial layer, the source region being doped with impurity of the first conductivity type at a doping concentration greater than the doping concentration of the epitaxial layer generally; the trench including a gate, the gate comprising an electrically conductive material, the electrically conductive material of the gate being in contact with the epitaxial layer at a portion of a sidewall of each trench; and a dielectric sidewall spacer located at an upper portion of the sidewall of each trench.