Junction Barrier Schottky Rectifier

摘要

A junction barrier Schottky rectifier with first and second drift layer sections, wherein a peak net doping concentration of the first section is at least two times lower than a minimum net doping concentration of the second section. For each emitter region the first section includes a layer which is in contact with the respective emitter region to form a pn-junction between the first section and the respective emitter region, wherein the thickness of this layer in a direction perpendicular to the interface between the first section and the respective emitter region is at least 0.1 μm. The JBS rectifier has a transition from unipolar to bipolar conduction mode at a lower forward bias due to lowering of electrostatic forces otherwise impairing the transport of electrons toward the emitter regions under forward bias conditions, and with reduced snap-back phenomenon.

主权项

1. A junction barrier Schottky rectifier comprising:
a substrate layer having a first conductivity type; a drift layer having the first conductivity type, wherein the drift layer is on the substrate layer and has a lower peak net doping concentration than the substrate layer; a plurality of emitter regions in the drift layer adjacent to a first main side of the junction barrier Schottky rectifier, each emitter region having a second conductivity type different from the first conductivity type; a first metal contact layer forming a Schottky contact with the drift layer and an ohmic contact with each one of the emitter regions on the first main side of the junction barrier Schottky rectifier; and a second metal contact layer forming an ohmic contact with the substrate layer on a second main side of the junction barrier Schottky rectifier opposite to the first main side, wherein the drift layer includes a first drift layer section and a second drift layer section, wherein a peak net doping concentration of the first drift layer section is at least two times lower than a minimum net doping concentration of the second drift layer section, and for each emitter region the first drift layer section includes a layer section which is in contact with the respective emitter region to form a pn-junction between the first drift layer section and the respective emitter region, wherein the thickness of this layer section in a direction perpendicular to the interface between the first drift layer section and the respective emitter region is at least 0.1 μm, wherein each one of the emitter regions comprises a first emitter section and a second emitter section, wherein a peak net doping concentration of the second emitter region is at least two times higher than a peak net doping concentration of the first emitter section, and in each emitter region the second emitter section extends to the second drift layer section, while the first emitter section is separated from the second drift layer section by the first drift layer section.