A junction field-effect transistor (JFET) with a gate region that includes two separate sub-regions having material of different conductivity types and/or a Schottky junction that substantially suppresses gate current when the gate junction is forward-biased, as well as complementary circuits that incorporate such JFET devices.

A precursor cell for a transistor having a foundation structure, a mask structure, and a gallium nitride (GaN) PN structure is provided. The mask structure is provided over the foundation structure to expose a first area of a top surface of the foundation structure. The GaN PN structure resides over the first area and at least a portion of the mask structure and has a continuous crystalline structure with no internal regrowth interfaces. The GaN PN structure comprises a drift region over the first area, a control region laterally adjacent the drift region, and a PN junction formed between the drift region and the control region. Since the drift region and the control region form the PN junction having no internal regrowth interfaces, the GaN PN structure has a continuous crystalline structure with reduced regrowth related defects at the interface of the drift region and the control region.

A vertical double diffusion metal-oxide-semiconductor power device with high voltage start-up unit includes a vertical double diffusion metal-oxide-semiconductor power transistor and the high voltage start-up unit. The vertical double diffusion metal-oxide-semiconductor power transistor includes a first metal layer, a substrate layer with first conductivity type, an epitaxy layer with first conductivity type, a second metal layer, and a plurality of polysilicon layers. The substrate layer is formed on the first metal layer. The epitaxy layer is formed on the substrate layer. The plurality of polysilicon layers are formed on the epitaxy layer. The second metal layer is formed on the plurality of polysilicon layers and the epitaxy layer. The high voltage start-up unit is formed on the epitaxy layer, wherein the high voltage start-up unit is used for providing a two-dimensional direction start-up current to the vertical double diffusion metal-oxide-semiconductor power device.

An apparatus includes a junction field-effect transistor (JFET) and a set of one or more serially-connected diodes. The JFET includes a first layer including silicon of a first conductivity type, a gate, and first and second terminals. The gate includes a second layer formed on the first layer and including intrinsic amorphous hydrogenated silicon, a third layer formed on the second layer and including amorphous hydrogenated silicon of a second conductivity type, and a conductive layer formed on the third layer. Each of the first and second terminals includes a fourth layer formed on the first layer, the fourth layer including crystalline hydrogenated silicon of the first conductivity type, and a conductive layer formed on the fourth layer. Each of the serially-connected diodes has first and second terminals, a first of the serially-connected diodes having the first terminal connected to the second terminal of the JFET.

The present disclosure relates to semiconductor structures and, more particularly, to gated body transistors and methods of manufacture. The structure includes: at least one fin structure composed of semiconductor material and including a channel region between a source region and a drain region; and a gated body under the channel region of the at least one fin structure.