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; 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 level is bonded to the first level, where the bonded includes oxide to oxide bonds, where the second transistors each include at least two side-gates, and where through the first metal layers power is provided to at least one of the second transistors.

Methods of operating semiconductor memory devices with floating body transistors, using a silicon controlled rectifier principle are provided, as are semiconductor memory devices for performing such operations. A method of maintaining the data state of a semiconductor dynamic random access memory cell is provided, wherein the memory cell comprises a substrate being made of a material having a first conductivity type selected from p-type conductivity type and n-type conductivity type; a first region having a second conductivity type selected from the p-type and n-type conductivity types, the second conductivity type being different from the first conductivity type; a second region having the second conductivity type, the second region being spaced apart from the first region; a buried layer in the substrate below the first and second regions, spaced apart from the first and second regions and having the second conductivity type; a body region formed between the first and second regions and the buried layer, the body region having the first conductivity type; and a gate positioned between the first and second regions and adjacent the body region. The memory cell is configured to store a first data state which corresponds to a first charge in the body region in a first configuration, and a second data state which corresponds to a second charge in the body region in a second configuration. The method includes: providing the memory cell storing one of the first and second data states; and applying a positive voltage to a substrate terminal connected to the substrate beneath the buried layer, wherein when the body region is in the first state, the body region turns on a silicon controlled rectifier device of the cell and current flows through the device to maintain configuration of the memory cell in the first memory state, and wherein when the memory cell is in the second state, the body region does not turn on the silicon controlled rectifier device, current does not flow, and a blocking operation results, causing the body to maintain the second memory state.

An IC may include an array of memory cells formed in a semiconductor, including memory cells arranged in rows and columns, each memory cell may include a floating body region defining at least a portion of a surface of the memory cell, the floating body region having a first conductivity type; a buried region located within the memory cell and located adjacent to the floating body region, wherein the buried region has a second conductivity type, wherein the floating body region is bounded on a first side by a first insulating region having a first thickness and on a second side by a second insulating region having a second thickness, and a gate region above the floating body region and the second insulating region and is insulated from the floating body region by an insulating layer; and control circuitry configured to provide electrical signals to said buried region.

The semiconductor device includes: a transistor having an oxide semiconductor layer; and a logic circuit formed using a semiconductor material other than an oxide semiconductor. One of a source electrode and a drain electrode of the transistor is electrically connected to at least one input of the logic circuit, and at least one input signal is applied to the logic circuit through the transistor. The off-current of the transistor is preferably 1×10.sup.−13 A or less.

Some embodiments include apparatus and methods having a base; a memory cell including a body, a source, and a drain; and an insulation material electrically isolating the body, the source, and the drain from the base, where the body is configured to store information. The base and the body include bulk semiconductor material. Additional apparatus and methods are described.

A semiconductor device and a fabrication method thereof are provided. The semiconductor device includes a semiconductor body, a first doped region, a second doped region, a gate and a dielectric layer. The semiconductor body is disposed on a dielectric substrate and has a protrusion portion, a first portion and a second portion. The first portion and the second portion are respectively disposed at two opposite sides of the protrusion portion. The first doped region is disposed in a top of the protrusion portion. The second doped region is disposed in an end of the first portion far away from the protrusion portion. The gate is disposed on the first portion and adjacent to the protrusion portion. The dielectric layer is disposed between the gate and the protrusion portion, and between the gate and the first portion.

A semiconductor device, the device including: a plurality of transistors, where at least one of the plurality of transistors includes a first single crystal channel, where at least one of the plurality of transistors includes a second single crystal channel, where the second single crystal channel is disposed above the first single crystal channel, where at least one of the plurality of transistors includes a third single crystal channel, where the third single crystal channel is disposed above the second single crystal channel, where at least one of the plurality of transistors includes a fourth single crystal channel, and where the fourth single crystal channel is disposed above the third single crystal channel; and at least one region of oxide to oxide bonds.

A 3D integrated circuit device, including: a first transistor; a second transistor; and a third transistor, where the third transistor is overlaying the second transistor and the second transistor is overlaying the first transistor, where the first transistor controls the supply of a ground or a power signal to the third transistor, and where the first transistor, the second transistor and the third transistor are aligned to each other with less than 100 nm misalignment.

Systems, methods and apparatus are provided for a three-node access device in vertical three dimensional (3D) memory. An example method includes a method for forming arrays of vertically stacked memory cells, having horizontally oriented access devices and vertically oriented access lines. The method includes depositing alternating layers of a dielectric material and a sacrificial material in repeating iterations to form a vertical stack. An etchant process is used to form a first vertical opening exposing vertical sidewalls in the vertical stack adjacent a first region. The first region is selectively etched to form a first horizontal opening removing the sacrificial material a first horizontal distance back from the first vertical opening. A first source/drain material, a replacement channel material having backchannel passivation, and a second source/drain material are deposited in the first horizontal opening to form the three-node access device for a memory cell among the arrays of vertically stacked memory cells.

Systems, methods and apparatus are provided for a three-node access device in vertical three dimensional (3D) memory. An example method includes a method for forming arrays of vertically stacked memory cells, having horizontally oriented access devices and vertically oriented access lines. The three-node access devices include a first source/drain region (1) and a second source/drain region (2) separated by a channel and gates (3) opposing the channel, but do not have a direct, electrical body contact to a body region and/or channel of the access devices. The method includes depositing alternating layers of a dielectric material and a sacrificial semiconductor material in repeating iterations to form a vertical stack, a first region of the sacrificial semiconductor material in which to form a first and a second source/drain region separated laterally by a channel region. An etchant process is used to form a first vertical opening exposing vertical sidewalls in the vertical stack adjacent the first region. The first region is selectively etched to form a first horizontal opening removing the sacrificial semiconductor material a first horizontal distance back from the first vertical opening. A source/drain material, a channel material, and a first source/drain material are deposited in the first horizontal opening to form the three-node access device for a memory cell among the arrays of vertically stacked memory cells.