Thursday, March 31, 2011

US Patent 7915709 - Vertical nanowire bipolar junction transistor

So far most of the proposed transistor designs that use nanowires or nanotubes have been based on a field effect transistor design. However, for analog and high-frequency applications bipolar junction transistors are often preferred. This patent from NXP B.V. discloses an example of a nanowire bipolar transistor. Claim 1 reads:

1. A semiconductor device comprising

a semiconductor body with a bipolar transistor comprising an emitter region, a base region and a collector region of, respectively, a first conductivity type, a second conductivity type opposite to the first conductivity type, and the first conductivity type, characterized in that one of the emitter or collector regions comprises a nanowire the base region is formed at the surface of the semiconductor body by means of a layer-shaped region the other one of the emitter or collector regions is formed in the semiconductor body below the base region and the emitter or collector region comprising the nanowire is provided on the surface of the semiconductor body in such a manner that the longitudinal axis thereof extends perpendicularly to the surface of the semiconductor body.