Patent ID: 6064074
Filing Date: 2000-05-16
Classification: H01J

Abstract:
A semiconductor device for emitting electrons, comprising a semiconductor body with at least one pn junction between an n-type region adjacent to a main surface and a p-type region, in which electrons emitted from the semiconductor body are generated by applying a voltage in the reverse direction across the pn junction, a first part of the pn junction, at the location of an emissive part of the pn junction, extending substantially parallel to the main surface and locally having a lower breakdown voltage than a second part of the pn junction, the first part being separated from the main surface by a thin n-type region having such a thickness and doping that the depletion zone does not extend as far as the main surface at the breakdown voltage, but remains separated from said main surface by a surface layer which is sufficiently thin to pass generated electrons, characterized in that the second part of the pn junction locally has a decreased breakdown voltage.