US Patent 7915709 - Vertical nanowire bipolar junction transistor

http://www.freepatentsonline.com/7915709.html

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.

US Patent 7791108 - Nanowire tunneling transistor

http://ip.com/patent/US7791108

Conventional MOSFET devices are based on the formation of a semiconductor channel having a length and width that determines the transistor behavior. Usually the channel is defined in a substrate having opposite  doping than the source and drain regions (e.g. n-type vs. p-type) but this requires careful control of doping that is very difficult at the nanoscale. This patent from NXP B.V. teaches a type of semiconductor nanowire channel design with low channel (nanowire) doping and highly doped source and drain regions forming Schottky-type barriers in a design which may be easier to fabricate at nanoscale dimensions. Claim 1 reads:    

1. Transistor comprising a nanowire having a source and a drain separated by an intrinsic or lowly doped region,

wherein a potential barrier is formed at the interface of the intrinsic or lowly doped region and one of the source and the drain,

wherein a gate electrode is provided in the vicinity of the potential barrier such that the effective height and/or width of the potential barrier can be modulated by applying an appropriate voltage to the gate electrode.

US Patent 7709923 - Metal-base nanowire transistor

http://www.freepatentsonline.com/7709923.html

Several decades ago metal-base transistors were proposes as a replacement for the purely semiconductor bipolar transistors. This patent from NXP Semiconductor attempts to introduce a nanowire version of the metal base transistor to achieve higher speed switching. Claim 1 reads:

1. Transistor comprising

a first, a second electrode, and base electrode to control current flow between the first and second electrode,

wherein the first electrode is made from a semiconducting material,

wherein the base electrode is a metal layer deposited on top of the semiconducting material forming the first electrode,

characterized in that the second electrode is formed by a semiconducting nanowire being in electrical contact with the base electrode.