US Patent 7504708 High-frequency switching device

A high-frequency switching device comprises a connecting region having a first conductivity type, and a first barrier region bordering on the connecting region and having a second conductivity type. A semiconductor region border on the first barrier region and has a dopant concentration which is lower than a dopant concentration of the first barrier region or equal to zero. A second barrier region borders on the first semiconductor region and has the first conductivity type. A base region borders on the second barrier region and has the second conductivity type. A third barrier region borders on the semiconductor region and has the second conductivity type and a higher dopant concentration than the semiconductor region. An emitter region borders on the third barrier region and has the first conductivity type. A fourth barrier region borders on the semiconductor region and has the second conductivity type and a higher dopant concentration than the semiconductor region. A collector region borders on the fourth barrier region and has the first conductivity type.