Patent ID: 7247926
Filing Date: 2007-07-24
Classification: H01L

Abstract:
1. A high-frequency switching transistor comprising: a collector area, having a first conductivity type; a first barrier area bordering on the collector area, the first barrier area having a second conductivity type which differs from the first conductivity type; a semiconductor area adjacent to the first barrier area, the semiconductor area having a dopant concentration which is at least one of the group consisting of lower than a dopant concentration of the first barrier area and equal to zero; a second barrier area adjacent to the semiconductor area, the second barrier area having the first conductivity type; a base area adjacent to the second barrier area, the base area having the second conductivity type; a third barrier area adjacent to the semiconductor area, the third barrier area having the second conductivity type and a higher dopant concentration than the semiconductor area; and an emitter area adjacent to the third barrier area, the emitter area having the first conductivity type.