Abstract: In a semiconductor substrate surface, first and second trenches extending in parallel with each other in a bit line direction are provided. An insulation film for trench isolation is filled in the first and second trenches. A floating gate is provided between the first and second trenches on the semiconductor substrate. A sidewall spacer is provided on a sidewall surface, extending in the bit line direction, of the floating gate.

Abstract: In a non-volatile semiconductor memory device according to the present invention, a p type source region and a p type drain region are formed in the surface of an n well. A floating gate electrode and a control gate electrode are formed on a channel region with a tunnel oxide film interposed therebetween. According to this structure, a negative potential is applied to the drain region and a positive potential is applied to the control gate electrode when data is programmed, whereby electrons are injected from the drain region to the floating gate electrode by a band-to-band tunnel current induced hot electron injection current in the drain region. As a result, a non-volatile semiconductor memory device is provided which can prevent deterioration of the tunnel oxide film and which can be miniaturized.

Abstract: A memory cell array of a nonvolatile semiconductor memory device is provided with a bipolar transistor whose base is connected to a node between sources of two memory cell transistors. A memory cell SL decoder controls the potential level of an emitter of the bipolar transistor. A collector of the bipolar transistor is held at a ground potential. In a read operation, the emitter potential is so controlled that the bipolar transistor enters an ON state, and a current flowing through a channel of either memory cell transistor is amplified by the bipolar transistor to be read.

Abstract: A nonvolatile semiconductor memory device with trench isolation having sufficient capability of isolating memory cells is provided. A trench formed as a line in the main surface of semiconductor substrate is filled with a first insulating film. On semiconductor substrate on both sides of trench, a first gate electrode is provided with a first oxide film interposed. On the first gate electrode, a second gate electrode is provided with a second insulating film interposed. An angle formed by a side wall upper surface of trench and the surface of semiconductor substrate is smaller than 90.degree..

Abstract: In a nonvolatile semiconductor memory device, a memory cell array includes memory cell transistors and cell select transistors corresponding to the memory cell transistors, respectively. A memory cell SG decoder supplies a potential to a cell select line corresponding to the selected row. The cell select transistor opens and closes a conduction path of a current flowing between a bit line and a source line through the memory cell transistor in accordance with the potential on the cell select line. As a result, an influence by a leak current flowing from the unselected memory cell transistor in a read operation is suppressed.

Abstract: A nonvolatile semiconductor memory device has a plurality of p well regions in a memory cell array region. P well region is independently provided for each erase block. Each p well region is connected to a common well/source line driver, respectively. Well/source line driver is connected to a well/source power supply and a well/block decoder. Therefore, a nonvolatile semiconductor memory device which can inhibit a well disturbance in erase operation can be provided.

Abstract: Each nonvolatile transistor comprises a floating gate electrode, an ONO film and a control gate electrode. An upper surface of a silicon oxide film is positioned at a height between upper and lower surfaces of the floating gate electrode. The control gate electrode continuously extends on the floating gate electrode and the silicon oxide film in a prescribed arrangement direction.

Abstract: A memory cell transistor connects its drain with a corresponding subbit line. In a program operation, a selected subbit line is connected to a program main bit line. In a read operation, a selected subbit line is connected with the base of a bipolar transistor, so that a channel current of a selected memory cell transistor flows as a base current. The bipolar transistor amplifies this base current, and controls a current flowing through a read main bit line.

Abstract: In erasing, electrons are simultaneously injected into floating gates from sources of a plurality of memory cells. Thus, the threshold voltages of the plurality of memory cells are increased. In programming, electrons are emitted from a floating gate of a selected memory cell to a drain. Thus, the threshold voltage of the selected memory cell is reduced.

Abstract: In a non-volatile semiconductor memory device according to the present invention, a p type source region and a p type drain region are formed in the surface of an n well. A floating gate electrode and a control gate electrode are formed on a channel region with a tunnel oxide film interposed therebetween. According to this structure, a negative potential is applied to the drain region and a positive potential is applied to the control gate electrode when data is programmed, whereby electrons are injected from the drain region to the floating gate electrode by a band-to-band tunnel current induced hot electron injection current in the drain region. As a result, a non-volatile semiconductor memory device is provided which can prevent deterioration of the tunnel oxide film and which can be miniaturized.

Abstract: A method of manufacturing a semiconductor memory device having stacked capacitors is disclosed. After forming a capacitor isolating layer on an insulation layer and forming a contact hole in the insulation layer, a first conductive layer is formed on the insulating layer and the capacitor isolating layer and on an inner surface of the contact hole. The first conductive layer is partially etched and removed by using an etch-back technique to be isolated into a first capacitor portion and a second capacitor portion. A dielectric layer is formed on the first conductive layer. A second conductive layer is formed on the dielectric layer.

Abstract: In erasing, electrons are simultaneously injected into floating gates from sources of a plurality of memory cells. Thus, the threshold voltages of the plurality of memory cells are increased. In programming, electrons are emitted from a floating gate of a selected memory cell to a drain. Thus, the threshold voltage of the selected memory cell is reduced.

Abstract: A capacitor includes a polycrystalline silicon layer 1 as a lower electrode layer, a dielectric layer 112, and a polycrystalline silicon layer 113 as an upper electrode layer. The dielectric layer 112 is formed by an oxynitride film 2, a silicon nitride film 3 and a top oxide film 4. A film thickness t.sub.3 of the top oxide film 4 is controlled to be less than 20 .ANG.. Capacitance of the capacitor can be increased while improving the duration of life of the dielectric layer, resulting in a highly reliable capacitor.

Abstract: Disclosed is a semiconductor memory device in which defects in crystal in a junction region between a capacitor and a source/drain region, and a short channel effect of a transistor can be effectively reduced. The semiconductor memory device includes, on the side of a gate electrode at which the capacitor is connected, a sidewall formed to have a width larger than that of a sidewall on the side of a bit line, and a source/drain region to which the capacitor is connected and which is formed to have a diffusion depth larger than that of the opposite source/drain region. Therefore, the source/drain region effectively prevents defects in crystal from being produced in the junction region between the capacitor and the source/drain region connected to the capacitor and the sidewall effectively reduces the short channel effect.

Abstract: In erasing, electrons are simultaneously injected into floating gates from sources of a plurality of memory cells. Thus, the threshold voltages of the plurality of memory cells are increased. In programming, electrons are emitted from a floating gate of a selected memory cell to a drain. Thus, the threshold voltage of the selected memory cell is reduced.

Abstract: It is postulated that a nonvolatile semiconductor memory device of the present invention includes a charge pump. The nonvolatile semiconductor memory device includes a memory cell array unit having a plurality of memory transistors formed therein to store data. Each memory transistor has a drain region connected to a predetermined bit line BL which is connected to a write circuit. A charge pump is connected to the write circuit. A predetermined potential is applied to a memory transistor via the write circuit by this charge pump in a writing mode. A charge pump load control means for suppressing variation in the charge pump load is connected to a memory transistor or a well region in which the memory transistor is formed. Thus, the charge pump load can be stabilized to allow improvement of the writing or erasing characteristics of the nonvolatile semiconductor memory device.

Abstract: An object of the present invention is to achieve an improved flash memory which enables to simultaneously obtain high performance and reliability even with voltage V.sub.CC of 3.3 V or below. The device includes a memory cell 6, a V.sub.CC type transistor 7 and a V.sub.PP type transistor 8. Memory cell 6 includes a tunnel oxide film 2, a floating gate 3 and a control gate 4. A V.sub.CC type transistor 7 includes a first gate insulating film 9 and a first gate 10. A V.sub.PP type transistor 8 includes a second gate insulating film 11 and a second gate 12. An inequality, t(V.sub.CC)<t(TN)<t(V.sub.PP), is satisfied where t(TN) is the thickness of the tunnel oxide film, t(V.sub.CC) is the thickness of the first gate insulating film, and t(V.sub.PP) is the thickness of the second gate insulating film.

Abstract: A method of manufacturing a semiconductor memory device having stacked capacitors is disclosed. After forming a capacitor isolating layer on an insulation layer and forming a contact hole in the insulation layer, a first conductive layer is formed on the insulating layer and the capacitor isolating layer and on an inner surface of the contact hole. The first conductive layer is partially etched and removed by using an etch-back technique to be isolated into a first capacitor portion and a second capacitor portion. A dielectric layer is formed on the first conductive layer. A second conductive layer is formed on the dielectric layer.

Abstract: A nonvolatile semiconductor memory device is provided including a DINOR (Divided Bit Line NOR) type cell that allows further reduction of the cell size while ensuring immunity from drain-disturb. In the nonvolatile semiconductor memory device, a sub-bit line is formed to have a length corresponding to the length of 16-1024 memory cell transistors. Memory cell transistors corresponding to the length of that sub-bit line are connected to the sub-bit line. Thus, the effective cell size is reduced while ensuring immunity from drain-disturb.

Abstract: In a semiconductor memory device according to the present invention, a conductive layer is formed on a field oxide film in a boundary region on the main surface of a semiconductor substrate. A floating gate electrode, an interlayer insulating film, and a control gate electrode are formed on the semiconductor substrate in a memory cell array region with a gate insulating film interposed therebetween. A gate electrode is formed in a peripheral circuit region with the gate insulating film interposed therebetween. An interlayer insulating film is formed on the conductive layer, the gate electrode, and the control gate electrode. A contact hole is formed at a predetermined position of the interlayer insulating film. An interconnection layer is selectively formed on the interlayer insulating film including the inner surface of the contact hole. According to the present invention, it is possible to prevent formation of a concave portion on the surface of the field oxide film in the boundary region.