Semiconductor device with alternate p-n and Schottky junctions

摘要

In a semiconductor device with external anode and cathode contacts, a near-surface arrangement of alternate Schottky junctions and p-n junctions and, between the junctions, lightly doped semiconductor material drift zones, the energy difference between the bandgap (Egap) in the electronic excitation spectrum of the drift zone semiconductor (2) and the energy level ( phi barrier) of the Schottky barrier (5) in the zero voltage state of the device is /- 0.8 (preferably /- 1) eV. Preferably, the drift zone semiconductor material (2, 10) is silicon carbide, gallium nitride, aluminium nitride or diamond. Also claimed is production of the above device by: (a) providing a silicon carbide substrate, containing /-10<18> cm<-3> of a first dopant, with a silicon carbide layer containing 10<14>-10<17> cm<-3> of a second dopant of the same charge carrier type by homoepitaxial deposition; (b) introducing a third dopant of complementary charge carrier type into the silicon carbide layer surface remote from the substrate in a structured manner by diffusion and/or ion implantation to form p-n junctions; (c) thermally treating the device at 1400-1700 deg C; (d) applying a first metallic layer onto the implanted surface to form a Schottky contact and applying a second metallic layer to form an ohmic contact; and (e) structuring the first and second layers.