Abstract: Non-volatile memory devices have a page buffer that can verify pre-erase. A non-volatile memory device may include a cell array having a plurality of strings consisting of memory cells disposed at the intersection regions of bit lines and word lines, and a plurality of page buffers connected to the bit lines through a sensing line.

Abstract: Disclosed herein is a NAND flash memory device capable of changing a block size. In NAND flash memory devices capable of changing a block size, each memory block is divided into two page groups. Each memory block includes two block switches to select each page group in response to an external address signal. During an erasing operation, the block size is easily variable by applying an erasure voltage to one or two page groups.

Abstract: Disclosed are a page buffer of a flash memory device and data program method using the same. After two data are sequentially stored in a main register (first latch) and a cache register (second latch) provided in a page buffer, they are respectively transferred to an even bit line and an odd bit line at the same time, and a bias needed for a program is applied to cells connected to the even bit line and the odd bit line, respectively, whereby the program is performed at the same time. Therefore, the number and time of operations for data loading, program operation and program verification can be reduced by half and the operating speed of the device can be improved.

Abstract: Disclosed is the flash memory device capable of repairing the word line. Fail word lines are repaired using redundancy cells for repairing bit lines by combining X/Y addresses, whereby repair in the direction of the bit line as well as repair in the direction of the word line is made possible. Therefore, it is possible to prevent degradation in the yield and improve reliability of the device.

Abstract: Disclosed is the flash memory device capable of repairing the word line. Fail word lines are repaired using redundancy cells for repairing bit lines by combining X/Y addresses, whereby repair in the direction of the bit line as well as repair in the direction of the word line is made possible. Therefore, it is possible to prevent degradation in the yield and improve reliability of the device.

Abstract: There is disclosed a code addressable memory (“CAM”) cell in a flash memory device. In order to stabilize the operation of the CAM cell in a flash memory device operating at a low voltage, the present invention manufactures a CAM cell in which a floating gate is formed to extend on more than two active regions and more than two cell arrays are connected in parallel commonly using a source region and a drain region. Therefore, the present invention can increase the gate-coupling ration of the CAM cell, thus stabilizing the operation of the CAM cell at a device for low-voltage use.

Abstract: There is disclosed a method of manufacturing a flash memory device. In order to solve the problems that expensive photograph equipments are required and the manufacturing costs are thus increased when defining a floating gate and a control gate in a flash memory cell used in a high-integration flash memory device, the present invention performs an etching process for defining a floating gate with an-isotropic etching process. Therefore, it can minimize the areas of a cell and thus obtain a high-integration device.

Abstract: There is disclosed a method of programming a flash memory cell, which is performed applying a given voltage a gate and a drain and maintaining a source and a substrate at a ground potential. The method variably applies a given voltage, with two or more steps, to one of the gate and drain terminals while applying a given voltage to the other of the gate and drain terminals, thus reducing the programming current per cell. Accordingly, the present invention can improve reliability and throughput of the flash memory cell.