A method for producing a 3D semiconductor device including: providing a first level including a first single crystal layer; forming peripheral circuitry in and/or on the first level, and includes first single crystal transistors; forming a first metal layer on top of the first level; forming a second metal layer on top of the first metal layer; forming second level disposed on top of the second metal layer; performing a first lithography step; forming a third level on top of the second level; performing a second lithography step; processing steps to form first memory cells within the second level and second memory cells within the third level, where the plurality of first memory cells include at least one second transistor, and the plurality of second memory cells include at least one third transistor; and deposit a gate electrode for second and third transistors simultaneously.

A semiconductor structure includes a field effect transistor (FET) having a source/drain, a contact in contact with the source/drain, and a buried power rail including a conductive material, wherein the buried power rail is in contact with the contact, wherein a first portion of the buried power rail closest to the contact has a first thickness, and wherein a second portion of the buried power rail has a second thickness such that the first thickness is less than the second thickness.

A method for producing a 3D memory device, the method including: providing a first level including a first single crystal layer and control circuits; forming at least one second level above the first level; performing a first etch step including etching holes within the second level; forming at least one third level above the at least one second level; performing a second etch step including etching holes within the third level; and performing additional processing steps to form a plurality of first memory cells within the second level and a plurality of second memory cells within the third level, where each of the first memory cells include one first transistor, where each of the second memory cells include one second transistor, where at least one of the first or second transistors has a channel, a source, and a drain having a same doping type.

A method for producing a 3D memory device including: providing a first level including a single crystal layer and control circuits, where the control circuits include a plurality of first transistors; forming at least one second level above the first level; performing a first etch step including etching holes within the second level; performing processing steps to form a plurality of first memory cells within the second level, where each of the first memory cells include one of a plurality of second transistors, where the control circuits include memory peripheral circuits, where at least one first memory cell is at least partially atop a portion of the memory peripheral circuits, and where fabrication processing of the first transistors accounts for a temperature and time associated with processing the second level and the plurality of second transistors by adjusting a process thermal budget of the first level accordingly.

A method of forming a semiconductor device includes forming a wafer having an ion-implanted silicon layer, wherein the ion-implanted silicon layer is disposed between a first insulator layer and a second insulator layer inside the wafer; forming an active region over the ion-implanted silicon layer; forming an active device in the active region; and forming a conductive via to couple the ion-implanted silicon layer and the active device.

A method of forming a semiconductor device includes forming a wafer having an ion-implanted silicon layer, wherein the ion-implanted silicon layer is disposed between a first insulator layer and a second insulator layer inside the wafer; forming an active region over the ion-implanted silicon layer; forming an active device in the active region; and forming a conductive via to couple the ion-implanted silicon layer and the active device.

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 method for producing a 3D semiconductor device including: providing a first level including a first single crystal layer; forming peripheral circuitry in and/or on the first level, and includes first single crystal transistors; forming a first metal layer on top of the first level; forming a second metal layer on top of the first metal layer; forming second level disposed on top of the second metal layer; performing a first lithography step; forming a third level on top of the second level; performing a second lithography step; processing steps to form first memory cells within the second level and second memory cells within the third level, where the plurality of first memory cells include at least one second transistor, and the plurality of second memory cells include at least one third transistor; and deposit a gate electrode for second and third transistors simultaneously.

The present disclosure describes semiconductor devices and methods for forming the same. A semiconductor device includes nanostructures over a substrate and a source/drain region in contact with the nanostructures. The source/drain region is doped with a first-type dopant. The semiconductor device also includes a counter-doped structure in contact with the substrate and the source/drain region. The counter-doped structure is doped with a second-type dopant opposite to the first-type dopant.

The present disclosure describes semiconductor devices and methods for forming the same. A semiconductor device includes nanostructures over a substrate and a source/drain region in contact with the nanostructures. The source/drain region is doped with a first-type dopant. The semiconductor device also includes a counter-doped structure in contact with the substrate and the source/drain region. The counter-doped structure is doped with a second-type dopant opposite to the first-type dopant.