公开(公告)号：US6157572A

公开(公告)日：2000-12-05

申请号：US85680

申请日：1998-05-27

申请人： Sameer S. Haddad ,  Wing H. Leung ,  John Chen ,  Ravi S. Sunkavalli ,  Ravi P. Gutala ,  Jonathan S. Su ,  Vei-Han Chen ,  Colin S. Bill

发明人： Sameer S. Haddad ,  Wing H. Leung ,  John Chen ,  Ravi S. Sunkavalli ,  Ravi P. Gutala ,  Jonathan S. Su ,  Vei-Han Chen ,  Colin S. Bill

IPC分类号： G11C16/16 ,  G11C16/04

CPC分类号： G11C16/3445 ,  G11C16/16

摘要： A flash Electrically-Erasable Programmable Read-Only Memory (EEPROM) includes a plurality of floating gate transistor memory cells, a plurality of wordlines connected to the cells and a power supply for generating erase pulses. A controller controls the power supply to apply an erase pulse to all wordlines which are not deselected. Then, an erase verify procedure is applied to the cells in sequence. If all cells connected to a wordline pass the erase verify test, the wordline is deselected such that subsequent erase pulses will not be applied to the wordline and possibly cause the cells to become overerased. In one embodiment of the invention, erase verify is performed on all of the cells after an erase pulse is applied. The erase operation is completed when all cells pass erase verify. In another embodiment, erase verify is applied to each cell in sequence, with erase pulses being applied until each current cell passes erase verify. The wordlines can be deselected individually or in groups. The invention results in a tightening of the threshold voltage distribution of the cells.

摘要翻译： 闪存电可擦除可编程只读存储器（EEPROM）包括多个浮栅晶体管存储单元，连接到单元的多个字线和用于产生擦除脉冲的电源。 控制器控制电源以将擦除脉冲施加到未被取消选择的所有字线。 然后，按顺序对单元应用擦除验证程序。 如果连接到字线的所有单元都通过擦除验证测试，则字线被取消选择，使得后续的擦除脉冲不会被施加到字线并且可能导致单元变得过高。 在本发明的一个实施例中，在施加擦除脉冲之后对所有单元执行擦除验证。 当所有单元通过擦除验证时，擦除操作完成。 在另一实施例中，按顺序对每个单元施加擦除验证，其中施加擦除脉冲，直到每个当前单元通过擦除验证。 字母可以单独或分组取消选择。 本发明导致电池的阈值电压分布的紧缩。

公开(公告)号：US5875130A

公开(公告)日：1999-02-23

申请号：US085705

申请日：1998-05-27

申请人： Sameer S. Haddad ,  Wing H. Leung ,  John Chen ,  Ravi S. Sunkavalli ,  Ravi P. Gutala ,  Jonathan S. Su ,  Vei-Han Chan ,  Colin S. Bill

发明人： Sameer S. Haddad ,  Wing H. Leung ,  John Chen ,  Ravi S. Sunkavalli ,  Ravi P. Gutala ,  Jonathan S. Su ,  Vei-Han Chan ,  Colin S. Bill

IPC分类号： G11C16/10 ,  G11C16/34 ,  G11C13/00

CPC分类号： G11C16/3409 ,  G11C16/10 ,  G11C16/3404

摘要： A flash Electrically-Erasable Programmable Read-Only Memory (EEPROM) includes a semiconductor substrate, and a plurality of field effect transistor memory cells each having a source, drain, floating gate and control gate formed on the substrate. A controller controls a power source to apply an operational pulse to the drain of a cell, and apply a source to substrate bias voltage to the cell while the operational pulse is being applied thereto, the bias voltage having a value selected to reduce or substantially eliminate leakage current in the cell. The operational pulse can be an overerase correction pulse. In this case, a voltage which is substantially equal to the bias voltage is applied to the control gate for the duration of the overerase correction pulse. The operational pulse can also be a programming pulse. In this case, a voltage which is higher than the bias voltage is applied to the control gate of the selected wordline for the duration of the programming pulse. The bias voltage is preferably applied during both the overerase correction and programming pulses, reducing the power requirements and reducing the background leakage of the cells to a level at which program, read and overerase correction operations can be operatively performed.

摘要翻译： 闪存电可擦除可编程只读存储器（EEPROM）包括半导体衬底和多个场效应晶体管存储单元，每个具有形成在衬底上的源极，漏极，浮置栅极和控制栅极。 控制器控制电源以将操作脉冲施加到单元的漏极，并且在施加操作脉冲时将源施加到单元的衬底偏置电压，所述偏置电压具有被选择为减少或基本上消除的值 电池中的漏电流。 操作脉冲可以是过高修正脉冲。 在这种情况下，在过扫描校正脉冲的持续时间内，向控制栅极施加基本上等于偏置电压的电压。 操作脉冲也可以是编程脉冲。 在这种情况下，在编程脉冲的持续时间内，将高于偏置电压的电压施加到所选字线的控制栅极。 偏置电压优选地在过电压过程校正和编程脉冲期间都被施加，从而降低功率需求并将电池的背景泄漏减小到能够可操作地执行程序，读取和过电压校正操作的电平。

公开(公告)号：US5901090A

公开(公告)日：1999-05-04

申请号：US85552

申请日：1998-05-27

申请人： Sameer S. Haddad ,  Wing H. Leung ,  John Chen ,  Ravi S. Sunkavalli ,  Ravi P. Gutala ,  Jonathan S. Su ,  Colin S. Bill ,  Vei-Han Chen

发明人： Sameer S. Haddad ,  Wing H. Leung ,  John Chen ,  Ravi S. Sunkavalli ,  Ravi P. Gutala ,  Jonathan S. Su ,  Colin S. Bill ,  Vei-Han Chen

IPC分类号： G11C16/16 ,  G11C16/04

CPC分类号： G11C16/3409 ,  G11C16/16

摘要： A flash Electrically-Erasable Programmable Read-Only Memory (EEPROM) includes a plurality of field effect transistor memory cells each having a source, drain, floating gate and control gate, and a power source for supplying a plurality of voltages to the cells. A controller controls the power source to apply at least one erase pulse to the cells. Then, at least one overerase correction or "soft programming" pulse is applied to the cells during which the source, drain and control gate voltages of the cells are such that the threshold voltages of overerased cells will be increased, but least erased cells will not be disturbed. The overerase correction pulses thereby tighten the threshold voltage distribution. A source to substrate bias voltage is applied for the duration of the overerase correction pulses which reduces the background leakage of the cells to a level at which the overerase correction operation can be effectively performed, even in applications with low supply voltages.

摘要翻译： 闪存电可擦除可编程只读存储器（EEPROM）包括多个具有源极，漏极，浮动栅极和控制栅极的场效应晶体管存储单元，以及用于向单元提供多个电压的电源。 控制器控制电源向单元施加至少一个擦除脉冲。 然后，将至少一个过度校正或“软编程”脉冲施加到单元，在该单元期间，单元的源极，漏极和控制栅极电压使得过度流过的单元的阈值电压将增加，但是最小擦除的单元将不会 被打扰 过度校正脉冲从而使阈值电压分布紧密。 在过渡期校正脉冲的持续时间内施加衬底偏置电压源，即使在具有低电源电压的应用中，也可以将电池的背景泄漏降低到可以有效执行过电压修正操作的水平。