A groove is formed in a first semiconductor layer 1, a sidewall of the groove is coated with a first insulating film 2, a first impurity layer 3 and a second impurity layer 4 thereon are disposed in the groove, a second semiconductor layer 7 is disposed on the second impurity layer, a first semiconductor is disposed at the other part, an n.sup.+ layer 6a and an n.sup.+ layer 6c are positioned at respective ends of the second semiconductor layer 7 and connected to a source line SL and a bit line BL, respectively, a first gate insulating layer 8 is formed on the second semiconductor layer 7, and a first gate conductor layer 9 is connected to a word line WL. Voltage applied to the source line SL, a plate line PL connected to the first semiconductor layer 1, the word line WL, and the bit line BL is controlled to perform data holding operation of holding, near the gate insulating layer, holes generated by an impact ionization phenomenon in a channel region 12 of the second semiconductor layer or by gate-induced drain leakage current, and data erase operation of removing the holes from the channel region 12.

A memory structure and methods for operating memory structures are provided. The memory structure includes a first, a second and a third gate structures disposed along a first direction and separated from each other, channel bodies having first ends and second ends, source regions separated from each other, having first conductivity types and connected to the first ends of the channel bodies respectively, drain regions separated from each other, having second conductivity types and connected to the second ends of the channel bodies respectively, and first side plugs disposed along a second direction, extending along a third direction, and electrically connected to the source regions and the channel bodies. The first gate structure includes island structures disposed along the second direction and extending along the third direction.

A semiconductor device according to an embodiment includes a substrate, first and second pillar electrodes extending along a vertical direction substantially perpendicular to a surface of the substrate, and a plurality of memory cells disposed between the first and second pillar electrodes. Each of the plurality of memory cells includes first and second shared device layers that are disposed adjacent to the first and second pillar electrodes, respectively, and extend along the vertical direction, first and second base device layers disposed between the first and second shared device layers, and a control gate electrode disposed on one of the first and second base device layers. Both first and second base device layers are disposed on a plane over the substrate and substantially parallel to the surface of the substrate.

A memory circuit with thyristor includes a plurality of memory cells. Each memory cell of the plurality of memory cells includes an access transistor and a thyristor. The thyristor is coupled to the access transistor. At least one of a gate of the access transistor and a gate of the thyristor has a fin structure.

Memory devices and methods of making memory devices are shown. Methods and configurations as shown provide folded and vertical memory devices for increased memory density. Methods provided reduce a need for manufacturing methods such as deep dopant implants.

A memory device based on thyristors, comprises the following elements. A plurality of gate structures, are continuous structures in the first direction. A plurality of bit lines, extending in a second direction substantially perpendicular to the first direction. A plurality of source lines, extending in the first direction. A plurality of channels, extending in a third direction substantially perpendicular to the first direction and the second direction, and penetrating the gate structures. The first doped regions of the channels are coupled to the bit lines, and the second doped regions of the channels are coupled to the source lines. A plurality of memory units formed by the gate structures and corresponding channels. The source lines are arranged in sequence according to the second direction to form a stair structure, and the lengths of the source lines decrease in sequence in the first direction.

Some embodiments include thyristors having first and second electrode regions, first and second base regions, and material having a bandgap of at least 1.2 eV in at least one of the regions. The first base region is between the first electrode region and the second base region, and the second base region is between the second electrode region and the first base region. The first base region interfaces with the first electrode region at a first junction, and interfaces with the second base region at a second junction. The second base region interfaces with the second electrode region at a third junction. A gate is along the first base region, and in some embodiments does not overlap either of the first and second junctions. Some embodiments include methods of programming thyristors, and some embodiments include methods of forming thyristors.

The access speeds of new memory technologies may not be compatible with product specifications of existing memory technologies such as DRAM, SRAM, and FLASH technologies. Their electrical parameters and behaviors are different such that they cannot meet existing memory core specifications without new architectures and designs to overcome their limitations. New memories such as STT-MRAM, Resistive-RAM, Phase-Change RAM, and a new class of memory called Vertical Layer Thyristor (VLT) RAM requires new read sensing and write circuits incorporating new voltage or current levels and timing controls to make these memory technologies work in today's systems. Systems and methods are provided for rendering the memory cores of these technologies transparent to existing peripheral logic so that they can be easily integrated.

Memory devices and methods of making memory devices are shown. Methods and configurations as shown provide folded and vertical memory devices for increased memory density. Methods provided reduce a need for manufacturing methods such as deep dopant implants.

A method of making stacked lateral semiconductor devices is disclosed. The method includes depositing a stack of alternating layers of different materials. Slots or holes are cut through the layers for subsequent formation of single crystal semiconductor fences or pillars. When each of the alternating layers of one material are removed space is provided for formation of single crystal semiconductor devices between the remaining layers. The devices are doped as the single crystal silicon is formed.