Abstract: High-density semiconductor memory is provided with enhancements to gate-coupling and electrical isolation between discrete devices in non-volatile memory. The intermediate dielectric between control gates and charge storage regions is varied in the row direction, with different dielectric constants for the varied materials to provide adequate inter-gate coupling while protecting from fringing fields and parasitic capacitances. Electrical isolation is further provided, at least in part, by air gaps that are formed in the column (bit line) direction and/or air gaps that are formed in the row (word line) direction.

Abstract: According to one embodiment, in a floating-gate type nonvolatile semiconductor memory device in which a tunnel dielectric film and a control gate electrode are connected between memory cells adjacent via a shallow trench isolation, each of a floating gate electrode and the control gate electrode includes an electric-field concentrated portion having a curvature on the tunnel dielectric film side. The electric-field concentrated portion of the floating gate electrode is formed over a forming position of a channel semiconductor. The electric-field concentrated portion of the control gate electrode is formed over a forming position of the shallow trench isolation.

Abstract: Air gap isolation in non-volatile memory arrays and related fabrication processes are provided. Electrical isolation can be provided, at least in part, by bit line air gaps that are elongated in a column direction and/or word line air gaps that are elongated in a row direction. The bit line air gaps may be formed in the substrate, extending between adjacent active areas of the substrate, as well as above the substrate surface, extending between adjacent columns of non-volatile storage elements. The word line air gaps may be formed above the substrate surface, extending between adjacent rows of non-volatile storage elements.

Abstract: A semiconductor device and method of manufacturing a semiconductor device include a plurality of first active regions and a second active region being formed on a substrate. The second active region is formed between two of the first active regions. A plurality of gate structures is formed on respective first active regions. A dummy gate structure is formed on the second active region, and a first voltage is applied to the dummy gate structure.

Abstract: A nonvolatile semiconductor memory transistor included in a nonvolatile semiconductor memory includes an island-shaped semiconductor having a source region, a channel region, and a drain region formed in this order from the substrate side, a hollow pillar-shaped floating gate arranged so as to surround the outer periphery of the channel region in such a manner that a tunnel insulating film is interposed between the floating gate and the channel region, and a hollow pillar-shaped control gate arranged so as to surround the outer periphery of the floating gate in such a manner that an inter-polysilicon insulating film is interposed between the control gate and the floating gate. The inter-polysilicon insulating film is arranged so as to be interposed between the floating gate and the upper, lower, and inner side surfaces of the control gate.

Abstract: A memory cell transistor includes a high dielectric constant tunnel insulator, a metal floating gate, and a high dielectric constant inter-gate insulator comprising a metal oxide formed over a substrate. The tunnel insulator and inter-gate insulator have dielectric constants that are greater than silicon dioxide. Each memory cell has a plurality of doped source/drain regions in a substrate. A pair of transistors in a row are separated by an oxide isolation region comprising a low dielectric constant oxide material. A control gate is formed over the inter-gate insulator.

Abstract: A non-volatile memory device includes a substrate having a first region and a second region. A first gate electrode is disposed on the first region. A multi-layered charge storage layer is interposed between the first gate electrode and the substrate, the multi-layered charge storage including a tunnel insulation, a trap insulation, and a blocking insulation layer which are sequentially stacked. A second gate electrode is placed on the substrate of the second region, the second gate electrode including a lower gate and an upper gate connected to a region of an upper surface of the lower gate. A gate insulation layer is interposed between the second gate electrode and the substrate. The first gate electrode and the upper gate of the second gate electrode comprise a same material.

Abstract: An isolation layer structure includes first to fourth oxide layer patterns. The first and third oxide layer patterns are sequentially formed in a first trench defined by a first recessed top surface of a substrate and sidewalls of gate structures on the substrate in a first region. The first trench has a first width, and the first and third oxide layer patterns have no void therein. The second and fourth oxide layer patterns are sequentially formed in a second trench defined by a second recessed top surface of the substrate and sidewalls of gate structures on the substrate in a second region. The second trench has a second width larger than the first width, and the fourth oxide layer pattern has a void therein.

Abstract: A memory device including a plurality of storage regions arranged with storage region intervals. A plurality of conductor lines are juxtaposed the storage region intervals. One or more isolations are provided, each isolation adjacent one or more conductor lines and juxtaposed one or more of the storage regions that are dummy storage regions. The storage regions are charge storage regions in memory cells and each memory cell further includes a first cell region, a second cell region and a cell channel juxtaposed the charge storage region and located between the first cell region and the second cell region. A first array region and a second array region are separated by a first one of the isolations; each array region includes one or more groups of the memory cells where each memory cell includes one of the storage regions.

Abstract: A memory device and method of making the memory device. The memory device comprises a storage transistor at a surface of a substrate. The storage transistor comprises a body portion between first and second source/drain regions, wherein the source/drain regions are regions of a first conductivity type. The storage transistor also comprises a gate structure that wraps at least partially around the body portion in at least two spatial planes. A bit line is connected to the first source/drain region and a word line is connected to the gate structure.

Abstract: A method for manufacturing on a substrate a semiconductor device with improved floating-gate to control-gate coupling ratio is described. The method comprises the steps of first forming an isolation zone in the substrate, thereafter forming the floating gate on the substrate, thereafter extending the floating gate using polysilicon spacers, and thereafter forming the control gate over the floating gate and the polysilicon spacers. Such a semiconductor device may be used in flash memory cells or EEPROMs.

Abstract: An electrically erasable programmable read only memory (EEPROM) is disclosed. The EEPROM includes a tunneling region in a semiconductor substrate, a control gate region in the semiconductor substrate and separated from the tunneling region by a device isolating layer, a tunnel oxide layer in a trench in the semiconductor substrate between the tunneling region and the control gate region, and a polysilicon layer on the tunnel oxide layer.

Abstract: A semiconductor storage element includes: a semiconductor layer constituted of a line pattern with a predetermined width formed on a substrate; a quantum dot forming an electric charge storage layer formed on the semiconductor layer through a first insulating film serving as a tunnel insulating film; an impurity diffusion layer formed in a surface layer of the semiconductor layer so as to sandwich the quantum dot therebetween; and a control electrode formed on the quantum dot through a second insulating film.

Abstract: A nonvolatile semiconductor memory device including a memory cell array of memory cells arranged in a matrix, each of which includes a selecting transistor and a memory cell transistor; a column decoder controlling the potential of bit lines; a voltage application circuit controlling the potential of the first word lines; a first row decoder controlling the potential of the second word lines; and a second row decoder controlling the potential of the source line. The column decoder is formed of a circuit whose withstand voltage is lower than the voltage application circuit and the second row decoder.

Abstract: A method of manufacturing a semiconductor device includes forming an oxidation film over a first and a second device region, forming an first etching preventing film extending over a first and a second area, removing the first etching preventing film over the first area; removing the oxidation film over the first device region, forming a first gate insulating film over the first device region, removing the oxidation film over the second device region, forming a second gate insulating film over the second device region, forming a first gate electrode over the first gate insulating film, forming a second gate electrode over the second gate insulating film, forming first source and drain regions in the first device region at both sides of the first gate electrode, and forming second source and drain regions in the second device region at both sides of the second gate electrode.

Abstract: Method of forming a semiconductor device which includes the steps of obtaining a semiconductor substrate having a logic region and an STI region; sequentially depositing layers of high K material, metal gate, first silicon and hardmask; removing the hardmask and first silicon layers from the logic region; applying a second layer of silicon on the semiconductor substrate such that the logic region has layers of high K material, metal gate and second silicon and the STI region has layers of high K material, metal gate, first silicon, hardmask and second silicon. There may also be a second hardmask layer between the metal gate layer and the first silicon layer in the STI region. There may also be a hardmask layer between the metal gate layer and the first silicon layer in the STI region but no hardmask layer between the first and second layers of silicon in the STI region.

Abstract: The performances of a semiconductor device are improved. Between a memory gate electrode and a p type well, and between a control gate electrode and the memory gate electrode of a split gate type nonvolatile memory, an insulation film having a charge accumulation layer therein is formed. The insulation film includes a lamination film of a silicon oxide film, a silicon nitride film formed thereover, another silicon oxide film formed thereover, and an insulation film formed thereover, and thinner than the upper silicon oxide film. The insulation film is in contact with the memory gate electrode including polysilicon. The insulation film is formed of a metal compound containing at least one of Hf, Zr, Al, Ta, and La, and hence can cause Fermi pinning, and has a high dielectric constant.

Abstract: A semiconductor device comprising a resistance element with a high resistance and high resistance accuracy and a non-volatile semiconductor storage element is rationally realized by comprising the non-volatile semiconductor storage element comprising a first isolation formed to isolate a first semiconductor area, a first insulator, and a first electrode in a self-aligned manner, and a second electrode, and the resistance element comprising a second isolation formed to isolate a second semiconductor area, a third insulator and a conductor layer in a self-aligned manner, and third and fourth electrodes formed on each end of the conductor layer via a fourth insulator, and connected with the conductor layer. The conductor layer or the third and fourth electrodes include the same material with the first or second electrode, respectively.

Abstract: A flash memory integrated circuit and a method for fabricating the same. A gate stack includes an initial oxide layer directly in contact with a silicon layer, defining an oxide-silicon interface therebetween. Additional oxide material is formed substantially uniformly along the oxide-silicon interface. Polysilicon grain boundaries at the interface are thereby passivated after etching. The interface can be is formed between a tunnel oxide and a floating gate, and passivating the grain boundaries reduces erase variability. Oxide in an upper storage dielectric layer is enhanced in the dilute steam oxidation. The thin oxide layers serve as diffusion paths to enhance uniform distribution of OH species across the buried interfaces being oxidized.

Abstract: A method of manufacturing a semiconductor integrated circuit device includes defining a first area by forming a separating area on a substrate, and forming a tunnel film in the first area, a floating gate on the tunnel film, a first electrode in the separating area, a first film on the floating gate, a second film on the first electrode, a control gate on the first film, a second electrode on the second film, and source and drain areas in the first area. The method includes forming a first interlayer film to cover the control gate and the second electrode, forming, in the first interlayer film, a conductive via plug reaching the second electrode, and forming, on the first interlayer film, a second wiring electrically coupled to the second electrode via the conductive via plug, and a first wiring that is capacitively-coupled to the second wiring and to the second electrode.

Abstract: A nonvolatile semiconductor memory device includes a floating gate; an erasing gat; and a control gate. The floating gate is provided on a channel region of a semiconductor substrate through a first insulating layer. The erasing gate is provided on the floating gate through a second insulating layer. The control gate is provided beside the floating gate and the erasing gate through a third insulating layer. The floating gate is U-shaped.

Abstract: A semiconductor device includes a semiconductor substrate, a plurality of memory cells, a plurality of bit lines, and a plurality of source lines. The memory cells are located in the semiconductor substrate. Each of the memory cells includes a trench provided in the semiconductor substrate, an oxide layer disposed on a sidewall of the trench, a tunnel oxide layer disposed at a bottom portion of the trench, a floating gate disposed in the trench so as to be surrounded by the oxide layer and the tunnel oxide layer, and an erasing electrode disposed on an opposing side of the tunnel oxide layer from the floating gate. The bit lines and the source lines are alternately arranged on the memory cells in parallel with each other.

Abstract: A semiconductor device which has a semiconductor substrate, an isolation insulating film formed in the semiconductor substrate, a conductive pattern formed over the semiconductor substrate and the isolation insulating film, so that a side face of the conductive pattern is formed over the isolation insulating film, and an insulating film is formed over the isolation insulating film, the conductive pattern and the side face of the conductive pattern, and the side face of the conductive pattern comprises a notch.

Abstract: An EEPROM according to the present invention includes: a semiconductor layer of a first conductive type; and a first insulating film formed on the semiconductor layer. A first impurity region, a second impurity region, a third impurity region, a fourth impurity region, and a fifth impurity region of a second conductive type are formed in top layer portions of the semiconductor layer. On the first insulating film, a select gate, a first floating gate, and a second floating gate are respectively disposed opposite a region between the first impurity region and the second impurity region, a region between the second impurity region and the third impurity region, and a region between the third impurity region and the fourth impurity region. In the first insulating film, a first tunnel window and a second tunnel window are respectively formed at portions in contact with the first floating gate and the second floating gate.

Abstract: Techniques are disclosed herein for applying different process steps to single-level cell (SLC) blocks in a memory array than to multi-level cell (MLC) blocks such that the SLC blocks will have high endurance and the MLC blocks will have high reliability. In some aspects, different doping is used in the MLC blocks than the SLC blocks. In some aspects, different isolation is used in the MLC blocks than the SLC blocks. Techniques are disclosed that apply different read parameters depending on how many times a block has been programmed/erased. Therefore, blocks that have been cycled many times are read using different parameters than blocks that have been cycled fewer times.

Abstract: Memory cells including a semiconductor layer having at least two source/drain regions disposed below a surface of the semiconductor layer and separated by a channel region; a lower insulating layer disposed above the channel region; a charge storage layer disposed above the lower insulating layer; an upper insulating multi-layer structure disposed above the charge storage layer, wherein the upper insulating multi-layer structure comprises a polysilicon material layer interposed between a first dielectric layer and a second dielectric layer; and a gate disposed above the upper insulating multi-layer structure are described along with arrays thereof and methods of operation.

Abstract: Provided are a semiconductor device and a method of fabricating the same. The semiconductor device may include a charge storage structure and a gate. The charge storage structure is formed on a substrate. The gate is formed on the charge storage structure. The gate includes a lower portion formed of silicon and an upper portion formed of metal silicide. The upper portion of the gate has a width greater than that of the lower portion of the gate.

Abstract: A method of manufacturing a parallel redundant array of single-electron devices. The method includes (a) providing a mask for diffusing a plurality of n-doped regions defined by a first set of a plurality of active regions, (b) providing a mask for disposing a plurality of polysilicon gates defined by a second set of a plurality of exposed regions, wherein an offset between a first member of the plurality of the exposed region of the first set differs in offset from a second member of the plurality of the exposed region of the second set, and (c) fabricating the parallel redundant array of single-electron devices as a function of the offset.

Abstract: Disclosed here in is a flash memory device and a method of fabricating the same. In accordance with one aspect of the invention, a flash memory device includes first contact plugs formed over a semiconductor substrate between gate patterns. Second contact plugs are formed over the semiconductor substrate between gate patterns and disposed alternately with the first contact plugs. The second contact plugs having a height greater than the first contact plugs. First and second conductive pads are connected to the first contact plugs. First and second pad contact plugs are formed on extended edge portions of the first and second conductive pads. First bit lines are connected to the first and second pad contact plugs, and second bit lines are connected to the second contact plugs.

Abstract: A semiconductor memory in which each memory cell in a NAND flash memory includes a columnar floating gate formed on an element region with a gate insulating film interposed between the floating gate and the element region, diffusion layers formed at portions of the element region located below both sides of the floating gate, and a control gate formed so as to surround the floating gate with an IPD film interposed between the control gate and the floating gate, the IPD film formed on a side surface of the floating gate.

Abstract: A semiconductor device includes a semiconductor substrate, and nonvolatile memory cells, each of the cells including a channel region having a channel length and a channel width, a tunnel insulating film, a floating gate electrode, a control gate electrode, an inter-electrode insulating film between the floating and control gate electrodes, and an electrode side-wall insulating film on side-wall surfaces of the floating and control gate electrodes, the electrode side-wall insulating film including first and second insulating films having first and second dielectric constants, the first dielectric constant being higher than the second dielectric constant, the second dielectric constant being higher than a dielectric constant of a silicon nitride film, the first insulating film being in a central region of a facing region between the floating and control gate electrodes, the second insulating region being in the both end regions of the facing region and protruding from the both end portions.

Abstract: A memory cell comprising: a semiconductor substrate with a surface with a source region and a drain region disposed below the surface of the substrate and separated by a channel region; a tunneling barrier dielectric structure with an effective oxide thickness of greater than 3 nanometers disposed above the channel region; a conductive layer disposed above the tunneling barrier dielectric structure and above the channel region; a charge trapping structure disposed above the conductive layer and above the channel region; a top dielectric structure disposed above the charge trapping structure and above the channel region; and a top conductive layer disposed above the top dielectric structure and above the channel region are described along with devices thereof and methods for manufacturing.

Abstract: An integrated circuit device includes a substrate; a bottom electrode over the substrate wherein the bottom electrode is in or over a lowest metallization layer over the substrate; a blocking layer over the bottom electrode; a charge-trapping layer over the blocking layer; an insulation layer over the charge-trapping layer; a control gate over the insulation layer; a tunneling layer over the control gate; and a top electrode over the tunneling layer.

Abstract: An apparatus and method of an electrically programmable and erasable non-volatile memory cell with a deep N-well to isolate the memory cell from the substrate is disclosed. In one embodiment, a non-volatile memory apparatus includes at least one non-volatile memory cell fabricated on a P substrate, with a deep N-well located in the P substrate, while a P-well and an N-well are located in the deep N-well. The memory cell further includes a PMOS transistor located in the N-well, in which the PMOS transistor includes a PMOS gate-oxide, and an NMOS capacitor located in the P-well. The NMOS capacitor includes an N+ coupling region located in the P-well, and an NMOS gate-oxide. The memory cell further includes a floating gate comprised of a poly-silicon gate overlying the PMOS transistor and the NMOS capacitor.

Abstract: A nonvolatile semiconductor memory includes first and second memory cells having a floating gate and a control gate. The floating gate of the first and second memory cells is comprised a first part, and a second part arranged on the first part, and a width of the second part in an extending direction of the control gate is narrower than that of the first part. A first space between the first parts of the first and second memory cells is filled with one kind of an insulator. The control gate is arranged at a second space between the second parts of the first and second memory cells.

Abstract: A flash memory device wherein the floating gate of the flash memory is defined by a recessed access device. The use of a recessed access device results in a longer channel length with less loss of device density. The floating gate can also be elevated above the substrate a selected amount so as to achieve a desirable coupling between the substrate, the floating gate and the control gate comprising the flash cell.

Abstract: Provided are nonvolatile memory devices and a method of forming the same. A tunnel insulating pattern is provided on a substrate, and a floating gate is provided on the tunnel insulating pattern. A floating gate cap having a charge trap site is provided on the floating gate, and a gate dielectric pattern is provided on the floating gate cap. A control gate is provided on the gate dielectric pattern.

Abstract: A NOR flash memory has a plurality of memory cell transistors, wherein each memory cell transistor shares the source diffusion layer with another memory cell transistor adjacent thereto on one side thereof in the column direction and shares the drain diffusion layer with another memory cell transistor adjacent thereto on the other side thereof in the column direction, and the width of the source diffusion layer in the column direction is narrower than the width of the drain diffusion layer in the column direction.

Abstract: A flash memory device and a method for fabricating the same are disclosed. The flash memory device includes an ONO layer on a substrate, polysilicon gates on the ONO layer, a gate oxide layer on the substrate, the ONO layer and the polysilicon gates, and a low temperature oxide layer and polysilicon sidewall spacers on outer side surfaces of the polysilicon gates, except in a region between nearest adjacent polysilicon gates.

Abstract: Nonvolatile memory devices having a low off state leakage current and an excellent data retention time characteristics. The present invention provides a surrounding stacked gate fin field effect transistor nonvolatile memory structure comprising a silicon-on-insulator substrate of a first conductivity type and a fin active region projecting from an upper surface of the insulator. The structure further includes a tunnel oxide layer formed on the fin active region and a first gate electrode disposed on the tunnel oxide layer and upper surface of the insulator. Additionally, the structure includes an oxide/nitride/oxide (ONO) composite layer formed on the first gate electrode, a second gate electrode formed on the ONO composite layer and patterned so as to define a predetermined area of the ONO composite layer. The structure further includes a dielectric spacer formed on a sidewall of the second gate electrode and source/drain regions formed in the fin active region on both sides of the second gate electrode.

Abstract: A semiconductor memory includes memory cell transistors including a tunnel insulating film, a floating gate electrode, a first insulating film, a control gate electrode, and a first metal salicide film; low-voltage transistors having a first p-type source region and a first p-type drain region, a first gate insulating film, and a first gate electrode of an n conductivity type having the same dose of a first p-type impurity as with the first p-type source region; and high-voltage transistors having a second p-type source region and a second p-type drain region, a second gate insulating film thicker than the first gate insulating film, and a second gate electrode of an n conductivity type having the same dose of a second p-type impurity as with the second p-type source region.

Abstract: A nonvolatile memory device may include: a tunnel insulating layer on a semiconductor substrate; a charge storage layer on the tunnel insulating layer; a blocking insulating layer on the charge storage layer; and a control gate electrode on the blocking insulating layer. The tunnel insulating layer may include a first tunnel insulating layer and a second tunnel insulating layer. The first tunnel insulating layer and the second tunnel insulating layer may be sequentially stacked on the semiconductor substrate. The second tunnel insulating layer may have a larger band gap than the first tunnel insulating layer. A method for fabricating a nonvolatile memory device may include: forming a tunnel insulating layer on a semiconductor substrate; forming a charge storage layer on the tunnel insulating layer; forming a blocking insulating layer on the charge storage layer; and forming a control gate electrode on the blocking insulating layer.

Abstract: A semiconductor device which is formed in a self-aligned manner without causing a problem of misalignment in forming a control gate electrode and in which a leak between the control gate electrode and a floating gate electrode is not generated, and a manufacturing method of the semiconductor device are provided. A semiconductor device includes a semiconductor film, a first gate insulating film over the semiconductor film, a floating gate electrode over the first gate insulating-film, a second gate insulating film which covers the floating gate electrode, and a control gate electrode over the second gate insulating film. The control gate electrode is formed so as to cover the floating gate electrode with the second gate insulating film interposed therebetween, the control gate electrode is provided with a sidewall, and the sidewall is formed on a stepped portion of the control gate-electrode, generated due to the floating gate electrode.

Abstract: An integrated memory device, an integrated memory chip and a method for fabricating an integrated memory device is disclosed. One embodiment provides at least one integrated memory device with a drain, a source, a floating gate, a selection gate and a control gate, wherein the conductivity between the drain and the source can be controlled independently via the control gate.

Abstract: Methods of forming a gate structure for an integrated circuit memory device include forming a first dielectric layer having a dielectric constant of under 7 on an integrated circuit substrate. Ions of a selected element from group 4 of the periodic table and having a thermal diffusivity of less than about 0.5 centimeters per second (cm2/s) are injected into the first dielectric layer to form a charge storing region in the first dielectric layer with a tunnel dielectric layer under the charge storing region. A metal oxide second dielectric layer is formed on the first dielectric layer, the second dielectric layer. The substrate including the first and second dielectric layers is thermally treated to form a plurality of discrete charge storing nano crystals in the charge storing region and a gate electrode layer is formed on the second dielectric layer. Gate structures for integrated circuit devices and memory cells are also provided.

Abstract: An electrically erasable programmable read-only memory includes a first polysilicon layer, a second polysilicon layer and a third polysilicon layer, the first polysilicon layer and the third polysilicon layer forming a control gate and the second polysilicon layer forming a floating gate. The first polysilicon layer is horizontally disposed in series with the second polysilicon layer and is connected to the third polysilicon layer, so that the control gate encloses all of the floating gate except for a tunnel surface of the floating gate.

Abstract: A semiconductor storage element includes: a source region and a drain region provided in a semiconductor substrate; a tunnel insulating film provided on the semiconductor substrate between the source region and the drain region; a charge storage film provided on the tunnel insulating film; a block insulating film provided on the charge storage film; a gate electrode provided on the block insulating film; and a region containing a gas molecule, the region provided in a neighborhood of an interface between the charge storage film and the block insulating film.

Abstract: On object of the invention is to provide a non-volatile memory device, in which data can be added to the memory device after a manufacturing process and forgery and the like by rewriting can be prevented, and a semiconductor device including the memory device. Another object of the invention is to provide a highly-reliable, inexpensive, and nonvolatile memory device and a semiconductor device including the memory device. A memory element includes a first conductive layer, a second conductive layer, a first insulating layer with a thickness of 0.1 nm or more and 4 nm or less being in contact with the first conductive layer, and an organic compound layer interposed between the first conductive layer, the first insulating layer, and the second conductive layer.

Abstract: A two-transistor non-volatile memory cell is formed in a semiconductor body. A memory-transistor well is disposed within the semiconductor body. A switch-transistor well is disposed within the semiconductor body and is electrically isolated from the memory transistor well. A memory transistor including spaced-apart source and drain regions is formed within the memory-transistor well. A switch transistor including spaced-apart source and drain regions is formed within the switch-transistor well region. A floating gate is insulated from and self aligned with the source and drain regions of the memory transistor and switch transistor. A control gate is disposed above and aligned to the floating gate and with the source and drain regions of the memory transistor and the switch transistor.

Abstract: A semiconductor memory device according to an embodiment of the present invention includes a substrate, a first gate insulator formed on the substrate and serving as an F-N (Fowler-Nordheim) tunneling film, a first floating gate formed on the first gate insulator, a second gate insulator formed on the first floating gate and serving as an F-N tunneling film, a second floating gate formed on the second gate insulator, an intergate insulator formed on the second floating gate and serving as a charge blocking film, and a control gate formed on the intergate insulator, at least one of the first and second floating gates including a metal layer.