Abstract: An EEPROM device is described incorporating a field effect transistor and a control gate spaced apart on a first insulating layer, a second insulating layer formed over the field effect transistor and the control gate and a common floating gate on the second insulating layer over the channel of the field effect transistor and the control gate, the floating gate thus also forms the gate electrode of the field-effect transistor. The EEPROM devices may be interconnected in a memory array and a plurality of memory arrays may be stacked on upon another. The invention overcomes the problem of using a non-standard silicon-on-insulator (SOI) CMOS process to make EEPROM arrays with high areal density.

Abstract: An electrically erasable programmable read-only memory CEEPROM) includes a field effect transistor and a control gate spaced apart on a first insulating layer, a second insulating layer formed over the field effect transistor and the control gate and a common floating gate on the second insulating layer over the channel of the field effect transistor and the control gate, the floating gate thus also forms the gate electrode of the field-effect transistor. The EEPROM devices may be interconnected in a memory array and a plurality of memory arrays may be stacked on upon another. The invention overcomes the problem of using a non-standard silicon-on-insulator (SOI) CMOS process to make EEPROM arrays with high areal density.

Abstract: The objects of the present invention are accomplished by merging a MOS-FET device and a floating gate into a three dimensional trench structure. The trench device cell has four vertical sides and bottom. The bottom of the trench forms the channel region of the transfer FET of the EEPROM cell. The heavily doped source and drain regions are formed on two vertical sidewalls of the trench and oppositely face each other. The heavily doped regions cover the entire sidewall and have a depth which is greater than the trench depth so that the channel region is defined by the bottom of the trench. The remaining two vertical sidewalls of the trench are formed by isolation oxide. A first silicon dioxide layer covers the bottom of the trench and forms part of the gate oxide of the cell device. A second silicon dioxide layer covers the vertical sidewalls of the trench. The second silicon dioxide layer is relatively thin with respect to the gate oxide layer.

Abstract: A stacked gate memory cell for a memory cell array is disclosed that is constructed on a SOI substrate and contains a second control gate buried underneath the conducting channel of the cell in addition to a first wordline control gate that is disposed over a floating gate changing the voltage on the second control gate will modulate the potential of the floating channel, which allows a specific cell of the array to be selected and the programmed or erased by FN tunneling through the floating gate and channel without disturbing adjacent cells. While reading the information stored in the floating gate, the second control gate can also be used to prevent disturb. The second control gate is in parallel with the bit line and perpendicular with the first word line control gate. The floating gate and the cell is located at the cross point of the first and second control gates. Therefore, by varying the voltage on the first and second control gates only, the cell can be programmed or erased through FN tunneling.

Abstract: A structure and fabrication method for an EEPROM cell having dual channel regions and the floating and control gate folded inside a trench. The cell is built on a SOI film substrate and the bottom part of the floating gate is butted to oxide, which provides high coupling factor. Inside the trench, the floating gates are butted to the conducting channels on two sidewalls, respectively. On the other two sidewalls, the floating gate are butted to the source and drain elements (bit line). These two sidewalls are used as the injection regions of FN tunnelling between source/drain and the floating gate or the isolation regions between bit lines. Since FN tunnelling (program and erase) occurs at the two trench sidewalls against the source and drain, program/erase speed is increased by increasing trench depth while maintaining cell size constant.

Abstract: The present invention is directed to a one-transistor non-volatile DRAM cell having a two layer floating gate to allow the contents of a storage capacitor to be transferred to the floating gate during power interruptions. The first layer of the floating gate is separated from a storage node of the storage capacitor by a tunnel oxide to allow electron tunnelling between the floating gate and the storage capacitor. In another embodiment of the present invention, a dual electron injector structure is disposed between a one layer floating and the storage node to allow electrons to be injected between the floating gate and the storage node. In another embodiment of the present invention, an erase gate is implemented to remove the charge on the floating gate. The erase gate can be separated from the floating gate by a tunnel oxide or a single electron injector structure to allow electrons to travel from the floating gate to the erase gate.

Abstract: The present invention is directed to a one-transistor non-volatile DRAM cell having a two layer floating gate to allow the contents of a storage capacitor to be transferred to the floating gate during power interruptions. The first layer of the floating gate is separated from a storage node of the storage capacitor by a tunnel oxide to allow electron tunnelling between the floating gate and the storage capacitor. In another embodiment of the present invention, a dual electron injector structure is disposed between a one layer floating and the storage node to allow electrons to be injected between the floating gate and the storage node. In another embodiment of the present invention, an erase gate is implemented to remove the charge on the floating gate. The erase gate can be separated from the floating gate by a tunnel oxide or a single electron injector structure to allow electrons to travel from the floating gate to the erase gate.

Abstract: The objects of the present invention are accomplished by merging a MOSFET device and a floating gate into a three dimensional trench structure. The trench device cell has four vertical sides and bottom. The bottom of the trench forms the channel region of the transfer FET of the EEPROM cell. The heavily doped source and drain regions are formed on two vertical sidewalls of the trench and oppositely face each other. The heavily doped regions cover the entire sidewall and have a depth which is greater than the trench depth so that the channel region is defined by the bottom of the trench. The remaining two vertical sidewalls of the trench are formed by isolation oxide. A first silicon dioxide layer covers the bottom of the trench and forms part of the gate oxide of the cell device. A second silicon dioxide layer covers the vertical sidewalls of the trench. The second silicon dioxide layer is relatively thin with respect to the gate oxide layer.