A method for producing a 3D semiconductor device including: providing a first level, the first level including a first single crystal layer; forming first alignment marks and control circuits in and/or on the first level, where the control circuits include first single crystal transistors and at least two interconnection metal layers; forming at least one second level disposed above the control circuits; performing a first etch step into the second level; forming at least one third level disposed on top of the second level; performing additional processing steps to form first memory cells within the second level and second memory cells within the third level, where each of the first memory cells include at least one second transistor, where each of the second memory cells include at least one third transistor, and where the additional processing steps include depositing a gate electrode simultaneously for the second and third transistors.

A semiconductor device, the device including: a plurality of transistors, where at least one of the plurality of transistors includes a first single crystal source, channel, and drain, where at least one of the plurality of transistors includes a second single crystal source, channel, and drain, where the second single crystal source, channel, and drain is disposed above the first single crystal source, channel, and drain, where at least one of the plurality of transistors includes a third single crystal source, channel, and drain, where the third single crystal source, channel, and drain is disposed above the second single crystal source, channel, and drain, where at least one of the plurality of transistors includes a fourth single crystal source, channel, and drain, and where the first single crystal source or drain, and the second single crystal source or drain each include n+ doped regions.

A semiconductor device including: a plurality of transistors, where at least one of the transistors includes a first single crystal source, channel, and drain, where at least one of the transistors includes a second single crystal source, channel, and drain, where the second single crystal source, channel, and drain is disposed above the first single crystal source, channel, and drain, where at least one of the transistors includes a third single crystal source, channel, and drain, where the third single crystal source, channel, and drain is disposed above the second single crystal source, channel, and drain, where at least one of the transistors includes a fourth single crystal source, channel, and drain, where the fourth single crystal source, channel, and drain is disposed above the third single crystal source, channel, and drain, and where the fourth drain is aligned to the first drain with less than 40 nm misalignment.

A method for producing a 3D memory device, the method comprising: providing a first level comprising a single crystal layer; forming at least one second level above said first level; performing a first etch step comprising etching holes within said second level; forming at least one third level above said at least one second level; performing a second etch step comprising etching holes within said third level; performing additional processing steps to form a plurality of first memory cells within said second level and a plurality of second memory cells within said third level, wherein each of said first memory cells comprise one first transistor, wherein each of said second memory cells comprise one second transistor, wherein at least one of said first or second transistors has a channel, a source and a drain having the same doping type, and wherein said forming at least one third level comprises forming a window within said third level to allow lithography alignment through said third level to an alignment mark underneath.

A 3D semiconductor device, the device including: a first level including a first single crystal layer and first transistors, where the first transistors each include a single crystal channel; first metal layers interconnecting at least the first transistors; and a second level including a second single crystal layer and second transistors, where the second level overlays the first level, where the second transistors are horizontally oriented and include a gate dielectric, where the gate dielectric includes hafnium oxide, 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 and first transistors, where the first transistors each include a single crystal channel; first metal layers interconnecting at least the first transistors; and a second level including a second single crystal layer and second transistors, where the second level overlays the first level, where the second transistors are horizontally oriented and include a gate dielectric, where the gate dielectric includes hafnium oxide, 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 single crystal layer, a first metal layer, a second metal layer above the first metal layer, and a third metal layer above the second metal layer, where the second metal layer is significantly thicker than either the third metal layer or the first metal layer, where the third metal layer is precisely aligned to the first metal layer with less than 20 nm misalignment; a second level including a first array of first memory cells, each of the first memory cells include first transistors; a third level including a second array of second memory cells, each of the second memory cells include second transistors, where the second level is above the third level, where the second transistors are self-aligned to the first transistors, being processed following the same lithography step; and periphery circuits connected by the second metal to control the memory cells, where the periphery circuits are either underneath or atop the memory cells.

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

A method for producing a 3D memory device, the method comprising: providing a first level comprising a single crystal layer; forming at least one second level above said first level; performing a first etch step comprising etching holes within said second level; forming at least one third level above said at least one second level; performing a second etch step comprising etching holes within said third level; performing additional processing steps to form a plurality of first memory cells within said second level and a plurality of second memory cells within said third level, wherein each of said first memory cells comprise one first transistor, wherein each of said second memory cells comprise one second transistor, wherein at least one of said first or second transistors has a channel, a source and a drain having the same doping type, and wherein said forming at least one third level comprises forming a window within said third level to allow lithography alignment through said third level to an alignment mark underneath.