Abstract: Isolation between vertical thyristor memory cells in an array is improved with isolation regions between the vertical thyristor memory cells. The isolation regions are formed by electrically isolating cores surrounded by insulating material, such as silicon dioxide, in trenches between the memory cells. The electrically isolating cores may be tubes of air or conducting rods. Methods of constructing the isolation regions in a processes for manufacturing vertical thyristor memory cell arrays are also disclosed.

Abstract: Integrated circuit devices having multiple level arrays of thyristor memory cells are created using a stack of ONO layers through which NPNPNPN layered silicon pillars are epitaxially grown in-situ. Intermediate conducting lines formed in place of the removed nitride layer of the ONO stack contact the middle P-layer of silicon pillars. The silicon pillars form two arrays of thyristor memory cells, one stacked upon the other, having the intermediate conducting lines as common connections to both arrays. The stacked arrays can also be provided with assist-gates.

Abstract: A semiconductor structure for a DRAM is described having multiple layers of arrays of thyristor memory cells and associated peripheral circuitry. Memory cells in a vertical string extending through the layers have an electrical connection to one terminal of the memory cells in that string. Word lines couple the strings together. Each layer of the array also includes bit line connections to memory cells on that layer. Methods of fabricating the array are described.

Abstract: A method of writing data into a volatile thyristor memory cell array and maintaining the data with refresh is disclosed.

Abstract: Memory cells are formed with vertical thyristors to create a volatile memory array. Power consumption in such arrays is reduced or controlled with various techniques including encoding the data stored in the arrays.

Abstract: Isolation between vertical thyristor memory cells in an array is improved with isolation regions between the vertical thyristor memory cells. The isolation regions are formed by electrically isolating cores surrounded by insulating material, such as silicon dioxide, in trenches between the memory cells. The electrically isolating cores may be tubes of air or conducting rods. Methods of constructing the isolation regions in a processes for manufacturing vertical thyristor memory cell arrays are also disclosed.

Abstract: Operations with reduced current overall are performed on single thyristor memory cells forming a volatile memory cell cross-point array. A first voltage is applied across a first group of memory cells for the operation and a lower second voltage is applied across other groups of memory cells. The first voltage is then applied across a second group of memory cells while the second voltage is applied across the other groups including the first group of memory cells and repeated until the operations covers all the groups.

Abstract: A volatile memory array using vertical thyristors is disclosed together with methods of operating the array to read data from and write data to the array.

Abstract: A semiconductor structure for a DRAM is described having multiple layers of arrays of thyristor memory cells with silicon-germanium base regions. Memory cells in a vertical string extending through the layers have an electrical connection to one terminal of the memory cells in that string. Word lines couple the strings together. Each layer of the array also includes bit line connections to memory cells on that layer. Select transistors enable the use of folded bit lines. Methods of fabricating the array are described.

Abstract: A semiconductor structure for a DRAM is described having multiple layers of arrays of thyristor memory cells and associated peripheral circuitry. Memory cells in a vertical string extending through the layers have an electrical connection to one terminal of the memory cells in that string. Word lines couple the strings together. Each layer of the array also includes bit line connections to memory cells on that layer. Methods of fabricating the array are described.

Abstract: A semiconductor structure for a DRAM is described having multiple layers of arrays of memory cells. Memory cells in a vertical string extending through the layers have an electrical connection to one terminal of the memory cells in that string. Word lines couple the strings together. Each layer of the array also includes bit line connections to memory cells on that layer. Select transistors enable the use of folded bit lines. The memory cells preferably are thyristors. Methods of fabricating the array are described.

Abstract: A method of writing data into a volatile thyristor memory cell array and maintaining the data with refresh is disclosed.

Abstract: Single thyristor memory cells form a volatile memory array. A sense amplifier reads the state of the thyristor in a selected memory cell against a dummy cell through precharged lines.

Abstract: An MTP (Many Times Programmable) memory cell for integrated circuit memory arrays is described. The cell includes an MTP device and a thyristor interconnected so that the MTP device triggers the thyristor to turn on during a Read or Verify operation. The difference in threshold voltages between a data memory cell and a reference memory cell is used to determine the information in the data memory cell. Different memory cell structures may be constructed for different memory array requirements.

Abstract: Memory cells are formed with vertical thyristors to create a volatile memory array. Power consumption in such arrays is reduced or controlled for an operation on a set of memory cells in an array, sequentially engaging subsets of memory cells for the operation while keeping the remaining memory cells of the set on hold until all the memory cells of the set have been operated on.

Abstract: A two-transistor memory cell based upon a thyristor for an SRAM integrated circuit is described together with methods of operation. The memory cell can be implemented in different combinations of MOS and bipolar select transistors, or without select transistors, with thyristors in a semiconductor substrate with shallow trench isolation. Standard CMOS process technology can be used to manufacture the SRAM.

Abstract: Apparatus and methods for reducing minority carriers in a memory array are described herein. Minority carriers diffuse between ON cells and OFF cells, causing disturbances during write operation as well as reducing the retention lifetime of the cells. Minority Carrier Lifetime Killer (MCLK) region architectures are described for vertical thyristor memory arrays with insulation trenches. These MCLK regions encourage recombination of minority carriers. In particular, MCLK regions formed by conductors embedded along the cathode line of a thyristor array, as well as dopant MCLK regions are described, as well as methods for manufacturing thyristor memory cells with MCLK regions.

Abstract: Integrated circuit devices having multiple level arrays of thyristor memory cells are created using a stack of ONO layers through which NPNPNPN layered silicon pillars are epitaxially grown in-situ. Intermediate conducting lines formed in place of the removed nitride layer of the ONO stack contact the middle P-layer of silicon pillars. The silicon pillars form two arrays of thyristor memory cells, one stacked upon the other, having the intermediate conducting lines as common connections to both arrays. The stacked arrays can also be provided with assist-gates.

Abstract: Thyristor memory cell arrays and their fabrication have improved features. Assist-gates between thyristor memory cells in an array operate on both sides of an assist-gate. The assist-gates can be arranged in various ways for optimized performance and the materials of the assist-gate are selected to control the bias voltage of the assist-gate in operation. The PNPN (or NPNP) thyristor layers of the memory cell can be fabricated in different process flows according to manufacturing concerns and the dopant concentrations of the layers are selected to reduce temperature sensitivity of the memory cell.

Abstract: A volatile memory array using vertical thyristors is disclosed together with methods of operating the array to read data from and write data to the array.