| Patent application number | Description | Published |
|---|
| 20090168505 | SEMICONDUCTOR DEVICE - A phase change memory capable of highly reliable operations is provided. A semiconductor device has a memory array having a structure in which memory cells are stacked including memory layers using a chalcogenide material and diodes, and initialization conditions and write conditions are changed according to the layer in which a selected memory cell is positioned. The initialization conditions and write conditions (herein, reset conditions) are changed according to the operation by selecting a current mirror circuit according to the operation and by a control mechanism of a reset current in a voltage select circuit and the current mirror circuit. | 07-02-2009 |
| 20090251964 | NONVOLATILE SEMICONDUCTOR MEMORY DEVICE - A nonvolatile semiconductor memory device according to the present invention is a NAND-type flash memory which is electrically capable of programming/erasing. The nonvolatile semiconductor memory device has at least 3 or more memory cell columns in which a plurality of memory cells are connected in series, and these memory cell columns are adjacent to each other via a shallow trench isolation. And, a programming operation is performed individually to each of these memory cell columns. In this manner, a programming-prevent voltage is surely provided at on at least one side of both surfaces of the semiconductor substrate which are adjacent via a shallow trench isolation to the surface of the semiconductor substrate under the programming-prevented memory cell. Therefore, a miss-programming to an unselected memory cell can be largely reduced. | 10-08-2009 |
| 20090262574 | SEMICONDUCTOR DEVICE - A highly reliable large capacity phase change memory module is realized. A semiconductor device according to the present invention includes a memory array having a structure in which a storage layer using a chalcogenide material and a memory cell constituted of a diode are stacked, and an initialization condition and a rewriting condition are changed in accordance with the layer where a selected memory cell is located. A current mirror circuit is selected in accordance with an operation, and at the same time, the initialization condition and the rewriting condition (here, reset condition) are changed in accordance with the operation by a control mechanism of the reset current in a voltage selection circuit and a current mirror circuit. | 10-22-2009 |
| 20100058127 | SEMICONDUCTOR DEVICE - To realize a fast and highly reliable phase-change memory system of low power consumption, a semiconductor device includes: a memory device which includes a first memory array having a first area including a plurality of first memory cells and a second area including a plurality of second memory cells; a controller coupled to the memory device to issue a command to the memory device; and a condition table for storing a plurality of trial writing conditions. The controller performs trial writing in the plurality of second memory cells a plurality of times based on the plurality of trial writing conditions stored in the condition table, and determines writing conditions in the plurality of first memory cells based on a result of the trial writing. The memory device performs writing in the plurality of first memory cells based on the writing conditions instructed from the controller. | 03-04-2010 |
| 20110013447 | SEMICONDUCTOR DEVICE - A phase change memory capable of highly reliable operations is provided. A semiconductor device has a memory array having a structure in which memory cells are stacked including memory layers using a chalcogenide material and diodes, and initialization conditions and write conditions are changed according to the layer in which a selected memory cell is positioned. The initialization conditions and write conditions (herein, reset conditions) are changed according to the operation by selecting a current mirror circuit according to the operation and by a control mechanism of a reset current in a voltage select circuit and the current mirror circuit. | 01-20-2011 |
| 20110110150 | SEMICONDUCTOR DEVICE - A highly reliable large capacity phase change memory module is realized. A semiconductor device according to the present invention includes a memory array having a structure in which a storage layer using a chalcogenide material and a memory cell constituted of a diode are stacked, and an initialization condition and a rewriting condition are changed in accordance with the layer where a selected memory cell is located. A current mirror circuit is selected in accordance with an operation, and at the same time, the initialization condition and the rewriting condition (here, reset condition) are changed in accordance with the operation by a control mechanism of the reset current in a voltage selection circuit and a current mirror circuit. | 05-12-2011 |
