A memory device includes a page made up of plural memory cells arranged in a column on a substrate, and a page write operation is performed to hold positive hole groups generated by an impact ionization phenomenon, in a channel semiconductor layer by controlling voltages applied to a first gate conductor layer, a second gate conductor layer, a first impurity region, and a second impurity region of each memory cell contained in the page and a page erase operation is performed to remove the positive hole groups out of the channel semiconductor layer by controlling voltages applied to the first gate conductor layer, the second gate conductor layer, the first impurity region, and the second impurity region. The first impurity layer of the memory cell is connected with a source line, the second impurity layer is connected with a bit line, one of the first gate conductor layer and the second gate conductor layer is connected with a word line, and another is connected with a drive control line; during the write operation after the page erase operation, the positive hole group is formed in the channel semiconductor layer by an impact ionization phenomenon by controlling voltages applied to the word line, the drive control line, the source line, and the bit line; and an applied voltage/applied voltages of one or both of the word line and the drive control line is/are lowered with drops in a first threshold voltage of the first gate conductor layer and a second threshold voltage of the second gate conductor layer.

A semiconductor memory cell includes a floating body region configured to be charged to a level indicative of a state of the memory cell; a first region in electrical contact with said floating body region; a second region in electrical contact with said floating body region and spaced apart from said first region; and a gate positioned between said first and second regions. The cell may be a multi-level cell. Arrays of memory cells are disclosed for making a memory device. Methods of operating memory cells are also provided.

An n.sup.+ layer 3a connected to a source line SL at both ends, an n.sup.+ layer 3b connected to a bit line BL, a first gate insulating layer 4a formed on a semiconductor substrate 1 existing on an insulating film 2, a gate conductor layer 16a connected to a plate line PL, a gate insulating layer 4b formed on the semiconductor substrate, and a second gate conductor layer 5b connected to a word line WL and having a work function different from a work function of the gate conductor layer 16a are disposed on the semiconductor substrate, and data hold operation of holding, near a gate insulating film, holes generated by an impact ionization phenomenon or gate-induced drain leakage current inside a channel region 12 of the semiconductor substrate 1 and data erase operation of removing the holes from inside the substrate 1 and the channel region 12 are performed by controlling voltage applied to the source line SL, the plate line PL, the word line WL, and the bit line BL.

A 3D semiconductor device including: a first level including a single crystal silicon layer and a plurality of first transistors, the 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 is disposed above the third metal layer, where the second level includes a plurality of second transistors; a fourth metal layer disposed above 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, where the via has a diameter of less than 800 nm and greater than 5 nm, and where at least one of the plurality of second transistors includes a metal gate.

Methods of maintaining a state of a memory cell without interrupting access to the memory cell are provided, including applying a back bias to the cell to offset charge leakage out of a floating body of the cell, wherein a charge level of the floating body indicates a state of the memory cell; and accessing the cell.

In a semiconductor storage device including a plurality of memory cells formed at a laminated substrate including a support layer, an insulating layer on the support layer, and a semiconductor layer on the insulating layer, the plurality of memory cells each include a floating gate transistor and a selection transistor. The floating gate transistor includes a first source region, a first drain region, a first body region, a first body contact region, a floating gate insulating film, and a floating gate electrode, and the selection transistor includes a second source region, a second drain region, a second body region, a second body contact region insulated from the first body contact region, a selection gate insulating film, and a selection gate electrode.

Transistors having reduced parasitics and enhanced performance. In some embodiments, a transistor can include a source and a drain each implemented as a first type active region, and a gate implemented relative to the source and the drain such that application of a voltage to the gate results in formation of a conductive channel between the source and the drain. The transistor can further include a body configured to provide the conductive channel upon the application of the voltage to the gate. The body can be implemented as a second type active region that butts with the first type active region on the source side at a respective area not covered by the gate, and does not butt with the first type active region on the drain side at a respective area not covered by the gate.

A 3D semiconductor device including: a first single crystal layer with first transistors; overlaid by a first metal layer; a second metal layer overlaying the first metal layer and being overlaid by a third metal layer; a logic gates including at least the first metal layer interconnecting the first transistors; second transistors disposed atop the third metal layer; third transistors disposed atop the second transistors; a top metal layer disposed atop the third transistors; and a memory array including word-lines, and at least four memory mini arrays, where each of the memory mini arrays includes at least four rows by four columns of memory cells, where each of the memory cells includes at least one of the second transistors or third transistors, sense amplifier circuit(s) for each of the memory mini arrays, the second metal layer provides a greater current carrying capacity than the third metal layer.

A flash memory device includes a substrate, a semiconductor quantum well layer, a semiconductor spacer, a semiconductor channel layer, a gate structure, and source/drain regions. The semiconductor quantum well layer is formed of a first semiconductor material and is disposed over the substrate. The semiconductor spacer is formed of a second semiconductor material and is disposed over the first semiconductor channel layer. The semiconductor channel layer is formed of the first semiconductor material and is disposed over the semiconductor spacer. Thea gate structure is over the second semiconductor channel layer. The source/drain regions are over the substrate and are on opposite sides of the gate structure.

A semiconductor device, the device including: a first silicon layer including first single crystal silicon; an isolation layer disposed over the first silicon layer; a first metal layer disposed over the isolation layer; a second metal layer disposed over the first metal layer; a first level including a plurality of transistors, the first level disposed over the second metal layer, where the isolation layer includes an oxide to oxide bond surface, where the plurality of transistors include a second single crystal silicon region; and a third metal layer disposed over the first level, where a typical first thickness of the third metal layer is at least 50% greater than a typical second thickness of the second metal layer.