Hyundai Electronics Industries Co. Ltd.

Jae C An

Hee Youl Lee

Sung H Hong

Byung Jin Ahn

Hee Hyun Chang

Soo Min Cho

Mun Hwa Lee

There is disclosed a method of erasing a flash memory device. The present invention implements a dummy recovery operation after a recovery operation for recovering the threshold voltage of an over-erased memory cell is implemented. Therefore, it can reduce the flow of the leakage current through bit lines to thus improve the program characteristic of the device.

Method of erasing a flash memory device

The mask ROM of the present invention is manufactured in the following processes; forming a cell array in which all the cells will be driven as on-cells, forming a groove by etching some portions of the semiconductor substrate in the drain region of the specific on-cell among the on-cells on customer's request, and then practicing a source and drain ion implantation process.

Method of making a mask ROM with a groove

The present invention discloses a split gate type flash EEPROM cell and a method of manufacturing the same which can prevent over-erasure of the flash EEPROM cell and decrease the cell area by forming a floating gate in the form of a spacer on a side wall of a select gate and by forming a control gate to surround the select gate and the floating gate.

Method for manufacturing a flash EEPROM cell

The present invention discloses a method of manufacturing a nonvolatile memory device. According to the present invention, in a nonvolatile memory device in which an equal voltage is applied to the control gates formed along both sides of the bit lines, the continuity of the control gates can be enhanced by interconnecting these control gates inside the cell arrays, resulting in a higher integration of the device and a reduction of the production of resistance therein, thereby improving the yield of the device.

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Seoul, South Korea

Jae C An