A 3D semiconductor device, the device including: a first level including a first single crystal layer, the first level including first transistors, where each of the first transistors includes a single crystal channel; first metal layers interconnecting at least the first transistors; a second metal layer overlaying the first metal layers; and a second level including a second single crystal layer, the second level including second transistors, where the second level overlays the first level, where at least one of the second transistors includes a transistor channel, where the at least one of the second transistors transistor channel includes non-silicon atoms, where the second level is directly bonded to the first level, and where the bonded includes direct oxide-to-oxide bonds.

A 3D semiconductor device, the device including: a first level including a first single crystal layer, the first level including first transistors, where the first transistors each include a single crystal channel; first metal layers interconnecting at least the first transistors; a second metal layer overlaying the first metal layers; and a second level including a second single crystal layer, the second level including second transistors, where the second level overlays the first level, where the second transistors each include at least two side-gates, where the second level is bonded to the first level, and where the bonded includes oxide to oxide bonds.

A 3D semiconductor device, the device including: a first level including a first single crystal layer, the first level including first transistors, where each of the first transistors includes a single crystal channel; first metal layers interconnecting at least the first transistors; a second metal layer overlaying the first metal layers; and a second level including a second single crystal layer, the second level including second transistors, where the second level overlays the first level, where at least one of the second transistors includes a transistor channel, where the at least one of the second transistors transistor channel includes non-silicon atoms, where the second level is directly bonded to the first level, and where the bonded includes direct oxide-to-oxide bonds.

A semiconductor device includes a junction field effect transistor (JFET) on a silicon-on-insulator (SOI) substrate. The JFET includes a gate with a first gate segment contacting the channel on a first lateral side of the channel, and a second gate segment contacting the channel on a second, opposite, lateral side of the channel. The first gate segment and the second gate segment extend deeper in the semiconductor layer than the channel. The JFET further includes a drift region contacting the channel, and may include a buried layer having the same conductivity type as the channel, extending at least partway under the drift region.

A 3D semiconductor device, the device including: a first level including a first single crystal layer, the first level including first transistors, where the first transistors each include a single crystal channel; first metal layers interconnecting at least the first transistors; second metal layer overlaying the first metal layer, and a second level including a second single crystal layer, the second level including second transistors, where the second level overlays the first level, where the second transistors each include a High-k metal gate, where the second level is bonded to the first level, and where the bonded includes oxide to oxide bonds.

A semiconductor device, the device including: a first single crystal substrate and plurality of logic circuits, where the first single crystal substrate has a device area, where the device area is significantly larger than a reticle size, where the plurality of logic circuits include an array of processors, where the plurality of logic circuits include a first logic circuit, a second logic circuit, and third logic circuit, where the plurality of logic circuits include switching circuits to support replacing the first logic circuit and the second logic circuit by the third logic circuit; and a built-in-test-circuit (“BIST”), where the built-in-test-circuit is connected to test at least the first logic circuit and the second logic circuit.

A 3D semiconductor device including: a first level including a single crystal silicon layer and a plurality of first transistors each including a single crystal channel; a first metal layer overlaying the plurality of first transistors; a second metal layer overlaying the first metal layer; a third metal layer overlaying the second metal layer; a second level, where the second level overlays the first level and includes a plurality of second transistors; a fourth metal layer overlaying the second level; and a connective path between the fourth metal layer and either the third metal layer or the second metal layer, where the connective path includes a via disposed through the second level and has a diameter of less than 500 nm and greater than 5 nm, where the third metal layer is connected to provide a power or ground signal to at least one of the second transistors.

An integrated circuit includes a junction field-effect transistor formed in a semiconductor substrate. The junction field-effect transistor includes a drain region, a source region, a channel region, and a gate region. A first isolating region separates the drain region from both the gate region and the channel region. A first connection region connects the drain region to the channel region by passing underneath the first isolating region in the semiconductor substrate. A second isolating region separates the source region from both the gate region and the channel region. A second connection region connects the source region to the channel region by passing underneath the second isolating region in the semiconductor substrate.

A 3D semiconductor device, the device including: a first level including a plurality of first metal layers; a second level, where the second level overlays the first level, where the second level includes at least one single crystal silicon layer, where the second level includes a plurality of transistors, where each of the plurality of transistors includes a single crystal channel, where the second level includes a plurality of second metal layers, where the plurality of second metal layers include interconnections between the plurality of transistors, and where the second level is overlaid by a first isolation layer; and a connective path between the plurality of transistors and the plurality of first metal layers, where the connective path includes a via disposed through at least the single crystal silicon layer, and where the via has a diameter of less than 400 nm and greater than 5 nm.

A 3D semiconductor device including: a first single-crystal layer including a plurality of first transistors; at least one first metal layer disposed atop the plurality of first transistors; a second metal layer disposed atop the at least one first metal layer; a plurality of second transistors disposed atop the second metal layer; a plurality of third transistors disposed atop the plurality of second transistors; a plurality of fourth transistors disposed atop the plurality of third transistors; a third metal layer disposed atop the plurality of fourth transistors; a fourth metal layer disposed atop the third metal layer; a plurality of connecting metal paths from the fourth metal layer or the third metal layer to the second metal layer, where at least one of the plurality of third transistors is aligned to at least one of the plurality of first transistors with less than 40 nm alignment error.