发明授权
US5753950A Non-volatile memory having a cell applying to multi-bit data by double
layered floating gate architecture and programming/erasing/reading
method for the same
失效
具有通过双层浮栅结构应用于多位数据的单元的非易失性存储器以及用于其的编程/擦除/读取方法
- 专利标题: Non-volatile memory having a cell applying to multi-bit data by double layered floating gate architecture and programming/erasing/reading method for the same
- 专利标题(中): 具有通过双层浮栅结构应用于多位数据的单元的非易失性存储器以及用于其的编程/擦除/读取方法
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申请号: US630184申请日: 1996-04-10
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公开(公告)号: US5753950A公开(公告)日: 1998-05-19
- 发明人: Toshiaki Kojima
- 申请人: Toshiaki Kojima
- 申请人地址: IL Schaumburg
- 专利权人: Motorola, Inc.
- 当前专利权人: Motorola, Inc.
- 当前专利权人地址: IL Schaumburg
- 优先权: JPX7-121142 19950519
- 主分类号: G11C17/00
- IPC分类号: G11C17/00 ; G11C11/56 ; G11C16/02 ; G11C16/04 ; H01L21/8247 ; H01L27/115 ; H01L29/788 ; H01L29/792 ; G11C11/34
摘要:
An object of the present invention is to contribute to increase of storage capacity of a memory and to cope with an nonlinear parasitic resistance. The non-volatile memory have a cell applying to multi-bit data by means of a double layered floating gate architecture. The cell comprises: heavily doped layers (drains 3.sub.0 -3.sub.2 and source 2) being formed separated from each other along an arrangement direction L in a semiconductor substrate; a first floating gate 4A being disposed along a direction orthogonal to the direction L between the drains and source above the semiconductor substrate; second floating gates 4B.sub.1, 4B.sub.2 which respectively extend across the first floating gate above the first floating gate and lie along the direction L, close to the drain; program gates 6.sub.1, 6.sub.2 disposed correspondingly to one of the second floating gates; and a control gate 5 extending across the gate 4A above the gate 4A and being disposed along the direction L, close to the source.Since the second floating gates individually store carriers corresponding to a data bit and the first floating gate determines a threshold voltage in accordance with a sum amount of carriers stored in all of the second floating gates, two or more bits of data can be saved per one storage cell. It is possible to avoid influence of nonlinear parasitic resistance because a transistor formed by the first floating gate and the control gate is used exclusively for reading.
公开/授权文献
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