Abstract: According to example embodiments of inventive concepts, a non-volatile memory device includes a substrate including a second impurity region crossing a first impurity region, and channel regions extending in a vertical direction on the substrate. Gate electrodes may be separated from each other in a vertical direction and a horizontal direction along outer walls of the channel regions. A first insulating interlayer may be on the gate electrodes and the channel regions, where the first insulating interlayer defines a contact hole between at least one adjacent pair gate electrodes and a contact plug is formed in the contact hole to be electrically connected to the second impurity region. An etch stop layer pattern may be on the contact plug and the first insulating interlayer.

Abstract: A gate structure of a non-volatile memory device and a method of forming the same including a tunnel oxide layer pattern, a charge trap layer pattern, a blocking dielectric layer pattern having the uppermost layer including a material having a first dielectric constant greater than that of a material included in the tunnel oxide layer pattern, and first and second conductive layer patterns. The gate structure includes a first spacer to cover at least the sidewall of the second conductive layer pattern. The gate structure includes a second spacer covering the sidewall of the first spacer and the sidewall of the first conductive layer pattern and including a material having a second dielectric constant equal to or greater than the first dielectric constant. In the non-volatile memory device including the gate structure, erase saturation caused by back tunneling is reduced.

Abstract: Nonvolatile memory devices including memory cell arrays with first bit line regions and common source tapping regions which are alternately disposed on a substrate along a direction, a page buffer including second bit line regions aligned with the first bit line regions and page buffer tapping regions aligned with the common source tapping regions, and a plurality of bit lines spaced apart from one another and extending to the second bit line regions from the first bit line regions.

Abstract: A semiconductor device includes two floating gates, a control gate and a first dielectric layer. The floating gates are disposed on a semiconductor substrate. The control gate partially overlaps each of the floating gates, and a part of the control gate is disposed between the two floating gates. Furthermore, the first dielectric layer disposed between the two floating gates and the control gate has a fixed thickness.

Abstract: A NAND device has at least a 3×3 array of vertical NAND strings in which the control gate electrodes are continuous in the array and do not have an air gap or a dielectric filled trench in the array. The NAND device is formed by first forming a lower select gate level having separated lower select gates, then forming plural memory device levels containing a plurality of NAND string portions, and then forming an upper select gate level over the memory device levels having separated upper select gates.

Abstract: A memory device includes a plurality of semiconductor lines, such as body-tied fins, on a substrate. The lines including buried-channel regions doped for depletion mode operation. A storage structure lies on the plurality of lines, including tunnel insulating layer on the channel regions of the fins, a charge storage layer on the tunnel insulating layer, and a blocking insulating layer on the charge storage layer. A plurality of word lines overlie the storage structure and cross over the channel regions of the semiconductor lines, whereby memory cells lie at cross-points of the word lines and the semiconductor lines.

Abstract: A nonvolatile semiconductor memory of an aspect of the present invention including a plurality of first active areas which are provided in the memory cell array side-by-side in a first direction and which have a dimension smaller than a fabrication limit dimension obtained by lithography, a second active area provided between the first active areas adjacent in the first direction, a memory cell unit which is provided in each of the plurality of first active areas and which has memory cells and select transistors, and a linear contact which is connected to one end of the memory cell unit and which extends in the first direction, wherein an area in which the linear contact is provided is one semiconductor area to which the plurality of first active areas are connected by the plurality of second active areas, and the bottom surface of the linear contact is planar.

Abstract: In a nonvolatile semiconductor memory device, a stacked body is formed by alternately stacking dielectric films and conductive films on a silicon substrate and a plurality of through holes extending in the stacking direction are formed in a matrix configuration. A shunt interconnect and a bit interconnect are provided above the stacked body. Conductor pillars are buried inside the through holes arranged in a line immediately below the shunt interconnect out of the plurality of through holes, and semiconductor pillars are buried inside the remaining through holes. The conductive pillars are formed from a metal, or low resistance silicon. Its upper end portion is connected to the shunt interconnect and its lower end portion is connected to a cell source formed in an upper layer portion of the silicon substrate.

Abstract: A semiconductor device includes a plurality of conductive layers and a plurality of insulating layers formed alternately with each other, at least one channel layer passing through the plurality of conductive layers and the plurality of insulating layers, and at least one first charge blocking layer surrounding the at least one channel layer, wherein a plurality of first regions, interposed between the at least one channel layer and the plurality of conductive layers, and a plurality of second regions, interposed between the at least one channel layer and the plurality of insulating layers, are alternately defined on the at least one first charge blocking layer, and each of the plurality of first regions has a greater thickness than each of the plurality of second regions.

Abstract: A semiconductor device includes a memory element including a stack structure stacking an insulator film and a metal film or a metal compound film; and a transistor including a gate structure having an identical stack structure as that of the memory element.

Abstract: Provided are a non-volatile memory devices having a stacked structure, and a memory card and a system including the same. A non-volatile memory device may include a substrate. A stacked NAND cell array may have at least one NAND set and each NAND set may include a plurality of NAND strings vertically stacked on the substrate. At least one signal line may be arranged on the substrate so as to be commonly coupled with the at least one NAND set.

Abstract: Embodiments described herein generally relate to methods of manufacturing charge-trapping memory by patterning the high voltage gates before other gates are formed. One advantage of such an approach is that a thin poly layer may be used to form memory and low voltage gates while protecting high voltage gates from implant penetration. One approach to accomplishing this is to dispose the layer of poly, and then dispose a mask and a thick resist to pattern the high voltage gates. In this manner, the high voltage gates are formed before either the low voltage gates or the memory cells.

Abstract: Provided are semiconductor devices and methods of forming the same. A device isolation structure in the semiconductor device includes a gap region. A dielectric constant of a vacuum or an air in the gap region is smaller than a dielectric constant of an oxide layer and, as a result coupling and attendant interference between adjacent cells may be reduced.

Abstract: In one embodiment, the semiconductor memory device includes a semiconductor substrate having projecting portions, a tunnel insulation layer formed over at least one of the projecting semiconductor substrate portions, and a floating gate structure disposed over the tunnel insulation layer. An upper portion of the floating gate structure is wider than a lower portion of the floating gate structure, and the lower portion of the floating gate structure has a width less than a width of the tunnel insulating layer. First insulation layer portions are formed in the semiconductor substrate and project from the semiconductor substrate such that the floating gate structure is disposed between the projecting first insulation layer portions. A dielectric layer is formed over the first insulation layer portions and the floating gate structure, and a control gate is formed over the dielectric layer.

Abstract: A lamination pattern having a control gate electrode, a first insulation film thereover, and a second insulation film thereover is formed over a semiconductor substrate. A memory gate electrode is formed adjacent to the lamination pattern. A gate insulation film is formed between the control gate and the semiconductor substrate. A fourth insulation film, including a lamination film of a silicon oxide film, a silicon nitride film, and another silicon oxide film, is formed between the memory gate electrode and the semiconductor substrate and between the lamination pattern and the memory gate electrode. At the sidewall on the side of the lamination pattern adjacent to the memory gate electrode, the first insulation film is retreated from the control gate electrode and the second insulation film, and the upper end corner portion of the control gate electrode is rounded.

Abstract: A nonvolatile memory cell is disclosed, having first and second semiconductor islands at the same horizontal level and spaced a predetermined distance apart, the first semiconductor island providing a control gate and the second semiconductor island providing source and drain terminals; a gate dielectric layer on at least part of the first semiconductor island; a tunneling dielectric layer on at least part of the second semiconductor island; a floating gate on at least part of the gate dielectric layer and the tunneling dielectric layer; and a metal layer in electrical contact with the control gate and the source and drain terminals. In one advantageous embodiment, the nonvolatile memory cell may be manufactured using an “all-printed” process technology.

Abstract: A semiconductor device fabrication method particularly suitable for the fabrication of a 90 nm embedded flash memory is disclosed. The method includes: forming a dielectric layer having a first thickness over a first device region and forming a dielectric layer having a second thickness different from the first thickness over a second device region, the dielectric layer having a first thickness serving as a tunnel oxide layer of a split-gate structure, the dielectric layer having a second thickness serving as a gate oxide layer of a MOS transistor. The method enables the fabrication of a MOS transistor including a gate oxide layer with a desired thickness.

Abstract: According to one embodiment, a nonvolatile semiconductor memory includes first to n-th (n is a natural number not less than 2) semiconductor layers in a first direction and extend in a second direction, and the semiconductor layers having a stair case pattern in a first end of the second direction, a common semiconductor layer connected to the first to n-th semiconductor layers commonly in the first end of the second direction, first to n-th layer select transistors which are provided in order from the first electrode side between the first electrode and the first to n-th memory strings, and first to n-th impurity regions which make the i-th layer select transistor (i is one of 1 to n) a normally-on state in the first end of the second direction of the i-th semiconductor layer.

Abstract: A memory device is provided, including a substrate, a conductive layer, a charge storage layer, a plurality of isolation structures, a plurality of first doped regions, and a plurality of second doped regions. The substrate has a plurality of trenches. The conductive layer is disposed on the substrate and fills the trenches. The charge storage layer is disposed between the substrate and the conductive layer. The isolation structures are disposed in the substrate between two adjacent trenches, respectively. The first doped regions are disposed in an upper portion of the substrate between each isolation structure and each trench, respectively. The second doped regions are disposed in the substrate under a bottom portion of the trenches, in which each isolation structure is disposed between two adjacent second doped regions.

Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes sheet-like memory strings arranged in a matrix shape substantially perpendicularly to a substrate. A control gate electrode film includes a common connecting section that extends in a first direction and an electrode forming section that is provided for each of memory cells above or below a floating gate electrode film via an inter-electrode dielectric film to project from the common connecting section in a second direction. The floating gate electrode film extends in the second direction and is formed on a first principal plane of a sheet-like semiconductor film via a tunnel dielectric film.

Abstract: A semiconductor memory includes a plurality of stripe-like active areas formed by stacking, in a direction perpendicular to a substrate, a plurality of layers extending parallel to the substrate, a first gate electrode formed on first side surfaces of the active areas, the first side surfaces being perpendicular to the substrate, a second gate electrode formed on second side surfaces of the active areas, the second side surfaces being perpendicular to the substrate. The layers are patterned in self-alignment with each other, intersections of the active areas and the first gate electrode form a plurality of memory cells, and the plurality of memory cells in an intersecting plane share the first gate electrode.

Abstract: There is provided a non-volatile semiconductor memory having a charge accumulation layer of a configuration where a metal oxide with a dielectric constant sufficiently higher than a silicon nitride, e.g., a Ti oxide, a Zr oxide, or a Hf oxide, is used as a base material and an appropriate amount of a high-valence substance whose valence is increased two levels or more (a VI-valence) is added to produce a trap level that enables entrance and exit of electrons with respect to the base material.

Abstract: In one embodiment of the invention, a memory includes wordline jogs and adjacent spacers. Spacers from different wordlines may contact one another on either side of a drain contact and consequently isolate and self-align the contact in the horizontal and vertical directions.

Abstract: Provided are a non-volatile memory device and a method of fabricating the same. The non-volatile memory device may include a substrate and a plurality of semiconductor pillars on the substrate. A plurality of control gate electrodes may be stacked on the substrate and intersecting the plurality of semiconductor pillars. A plurality of dummy electrodes may be stacked adjacent to the plurality of control gate electrodes on the substrate, the plurality of dummy electrodes being spaced apart from the plurality of control gate electrodes. A plurality of via plugs may be connected to the plurality of control gate electrodes. A plurality of wordlines may be on the plurality of via plugs. Each of the plurality of via plugs may penetrate a corresponding one of the plurality of control gate electrodes and at least one of the plurality of dummy electrodes.

Abstract: A three dimensional non-volatile memory structure includes a plurality of interlayer dielectric layers and a plurality of control gates alternately stacked over a substrate, a channel formed to penetrate the plurality of interlayer dielectric layers and the plurality of control gates, a tunnel insulating layer formed to surround the channel, a plurality of floating gates disposed between the plurality of interlayer dielectric layers and the tunnel insulating layer, wherein the plurality of floating gates each have a thickness greater than a corresponding one of the interlayer dielectric layers, and a charge blocking layer disposed between the plurality of control gates and the plurality of floating gates.

Abstract: A non-volatile memory including one or more EEPROM cell pairs. Each EEPROM cell pair includes three transistors and stores two data bits, effectively providing a 1.5 transistor EEPROM cell. An EEPROM cell pair includes a first non-volatile memory transistor connected to a first bit line, a second non-volatile memory transistor connected to a second bit line, and a source access transistor coupled to common source line. The source access transistor includes: a first diffusion region continuous with a source region of the first non-volatile memory transistor and a second diffusion region continuous with a source region of the second non-volatile memory transistor.

Abstract: A memory circuit arrangement and a fabrication method are disclosed. The memory circuit arrangement has a memory cell area. The memory cell area contains memory cell transistors, one column of which are selected using a triple gate area selection transistor. The transistor has gate area that extends into isolating trenches. The isolating trenches isolate the memory cell in different columns of the memory cell array.

Abstract: Hardened programmable logic devices are provided with programmable circuitry. The programmable circuitry may be hardwired to implement a custom logic circuit. Generic fabrication masks may be used to form the programmable circuitry and may be used in manufacturing a product family of hardened programmable logic devices, each of which may implement a different custom logic circuit. Custom fabrication masks may be used to hardwire the programmable circuitry to implement a specific custom logic circuit. The programmable circuitry may be hardwired in such a way that signal timing characteristics of a hardened programmable logic device that implements a custom logic circuit may match the signal timing characteristics of a programmable logic device that implements the same custom logic circuit using configuration data.

Abstract: According to one embodiment, a nonvolatile semiconductor memory includes a gate insulating film, a floating gate, first and second silicon oxide films, an insulating film and a control gate. The floating gate is formed on the gate insulating film. The first silicon oxide film is formed on an upper surface of the floating gate. The insulating film is formed on the first silicon oxide film on the upper surface of the floating gate and has a dielectric constant higher than that of the silicon oxide film. The second silicon oxide film is formed on the insulating film on the upper surface of the floating gate and on a side surface of the floating gate. The control gate is formed on the second silicon oxide film formed on the upper and side surfaces of the floating gate.

Abstract: A stacked memory device may include at least one memory unit and at least one peripheral circuit unit arranged either above or below the at least one memory unit. The at least one memory unit may include a memory string array, a plurality of bit lines, and a plurality of string selection pads. The memory string may include a plurality of memory strings arranged in a matrix and each of the memory strings may include a plurality of memory cells and a string selection device arranged perpendicular to a substrate. The plurality of bit lines may extend in a first direction and may be connected to ends of the plurality of memory strings. The plurality of string selection pads may be arrayed in a single line along the first direction and may be connected to the string selection devices included in the plurality of memory strings.

Abstract: Various lithography methods are disclosed. An exemplary lithography method includes forming a first patterned silicon-containing organic polymer layer over a substrate by removing a first patterned resist layer, wherein the first patterned silicon-containing organic polymer layer includes a first opening having a first dimension and a second opening having the first dimension, the first opening and the second opening exposing the substrate; forming a second patterned silicon-containing organic polymer layer over the substrate by removing a second patterned resist layer, wherein a portion of the patterned second silicon-containing organic polymer layer combines with a portion of the first patterned silicon-containing organic polymer layer to reduce the first dimension of the second opening to a second dimension; and etching the substrate exposed by the first opening having the first dimension and the second opening having the second dimension.

Abstract: Memory devices having an increased effective channel length and/or improved TPD characteristics, and methods of making the memory devices are provided. The memory devices contain two or more memory cells on a semiconductor substrate and bit line dielectrics between the memory cells. The memory cell contains a charge trapping dielectric stack, a poly gate, a pair of pocket implant regions, and a pair of bit lines. The bit line can be formed by an implant process at a higher energy level and/or a higher concentration of dopants without suffering device short channel roll off issues because spacers at bit line sidewalls constrain the implant in narrower implant regions.

Abstract: A nonvolatile memory device having a vertical structure and a method of manufacturing the same, the nonvolatile memory device including a channel region that vertically extends from a substrate; gate electrodes on the substrate, the gate electrodes being disposed along an outer side wall of the channel region and spaced apart from one another; and a channel pad that extends from one side of the channel region to an outside of the channel region, the channel pad covering a top surface of the channel region.

Abstract: A nonvolatile semiconductor memory device includes a plurality of floating gate electrodes respectively formed above a semiconductor substrate with first insulating films disposed therebetween, and a control gate electrode formed above the plurality of floating gate electrodes with a second insulating film disposed therebetween. In each of the plurality of floating gate electrodes is formed to have a width of an upper portion thereof in a channel width direction which is smaller than a width of a lower portion thereof in the channel width direction and one of contact surfaces thereof on at least opposed sides which contact the second insulating film is formed to have one surface, and the second insulating film has a maximum film thickness in a vertical direction, the maximum film thickness being set smaller than a distance from a lowest surface to a highest surface of the second insulating film in the vertical direction.

Abstract: A semiconductor device includes a substrate, a gate structure disposed on the substrate and which includes a gate insulating layer and a gate electrode layer, a first nitride layer disposed on the substrate and the gate structure and which includes silicon, and a second nitride layer that is disposed on the first nitride layer and has an atomic percentage of silicon less than that of the first nitride layer.

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 non-volatile programmable memory cell suitable for use in a programmable logic array includes a non-volatile MOS transistor of a first conductivity type in series with a volatile MOS transistor of a second conductivity type. The non-volatile MOS transistor may be a floating gate transistor, such as a flash transistor, or may be another type of non-volatile transistor such as a floating charge-trapping SONOS, MONOS transistor, or a nano-crystal transistor. A volatile MOS transistor, an inverter, or a buffer may be driven by coupling its gate or input to the common connection between the non-volatile MOS transistor and the volatile MOS transistor.

Abstract: A method of fabricating a memory device is provided that may begin with forming a layered gate stack atop a semiconductor substrate and patterning a metal electrode layer stopping on the high-k gate dielectric layer of the layered gate stack to provide a first metal gate electrode and a second metal gate electrode on the semiconductor substrate. In a next process sequence, at least one spacer is formed on the first metal gate electrode atop a portion of the high-k gate dielectric layer, wherein a remaining portion of the high-k gate dielectric is exposed. The remaining portion of the high-k gate dielectric layer is etched to provide a first high-k gate dielectric having a portion that extends beyond a sidewall of the first metal gate electrode and a second high-k gate dielectric having an edge that is aligned to a sidewall of the second metal gate electrode.

Abstract: A non-volatile semiconductor memory device includes a substrate, a first gate formed on a first region of a surface of the substrate, a second gate formed on a second region of the surface of the substrate, a charge storage layer filled between the first gate and the second gate, a first diffusion region formed on a first side of the charge storage layer, and a second diffusion region formed opposite the charge storage layer from the first diffusion region. The first region and the second region are separated by a distance sufficient for forming a self-aligning charge storage layer therebetween.

Abstract: A three-dimensional (3D) non-volatile memory (NVM) array including spaced-apart horizontally-disposed bitline structures arranged in vertical stacks, each bitline structures including a mono-crystalline silicon beam and a charge storage layer entirely surrounding the beam. Vertically-oriented wordline structures are disposed next to the stacks such that each wordline structure contacts corresponding portions of the charge storage layers. NVM memory cells are formed at each bitline/wordline intersection, with corresponding portions of each bitline structure forming each cell's channel region. The bitline structures are separated by air gaps, and each charge storage layer includes a high-quality thermal oxide layer that entirely covers (i.e., is formed on the upper, lower and opposing side surfaces of) each of the mono-crystalline silicon beams.

Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a substrate, a tunneling insulating film, a floating gate, a leak suppression unit, an inter-gate insulating film, and a control gate. The substrate includes silicon. The tunneling insulating film is provided on the substrate. The floating gate is provided on the tunneling insulating film. The leak suppression unit is provided on the floating gate. The inter-gate insulating film is provided on the leak suppression unit. The control gate is provided on the inter-gate insulating film. The dielectric constant of the leak suppression unit is higher than a dielectric constant of the inter-gate insulating film.

Abstract: A silicon on insulator (SOI) multi-gate field effect transistor electrically Programmable Read-Only Memory (MuFET EPROM) includes a substrate having a dielectric surface. A first semiconducting region is in or on the dielectric surface. A source region, a drain region and a channel region interposed between the source and drain are formed in first semiconducting region. A gate dielectric layer is on the channel region. At least a second semiconducting region in or on the dielectric surface is spaced apart from the first semiconducting region. A first electrode layer comprises a first electrode portion including a transistor gate electrode and a control gate electrode electrically isolated from one another. The transistor gate overlies the channel region to form a transistor. The control gate extends to overlay a portion of the second semiconducting region.

Abstract: A nonvolatile semiconductor memory device according to an embodiment includes memory strings which have a plurality of transistors including gate electrode films formed over sides of columnar semiconductor films on gate dielectric films in a height direction of the semiconductor films, and which are arranged in a matrix shape substantially perpendicularly above a substrate. The gate electrode films of the transistors at same height of the memory strings arranged in a first direction are connected to one another. A distance between the semiconductor films at least in a forming position of the transistor at an uppermost layer of the memory strings adjacent to each other in the first direction is smaller than double of thickness of the gate dielectric films.

Abstract: A nonvolatile semiconductor memory device includes a plurality of memory strings, each of which has a plurality of electrically rewritable memory cells connected in series; and select transistors, one of which is connected to each of ends of each of the memory strings. Each of the memory strings is provided with a first semiconductor layer having a pair of columnar portions extending in a perpendicular direction with respect to a substrate, and a joining portion formed so as to join lower ends of the pair of columnar portions; a charge storage layer formed so as to surround a side surface of the columnar portions; and a first conductive layer formed so as to surround the side surface of the columnar portions and the charge storage layer, and configured to function as a control electrode of the memory cells.

Abstract: A semiconductor device according to an embodiment, includes a dielectric film and an Si semiconductor part. The dielectric film is formed by using one of oxide, nitride and oxynitride. The Si semiconductor part is arranged below the dielectric film, having at least one element of sulfur (S), selenium (Se), and tellurium (Te) present in an interface with the dielectric film, and formed by using silicon (Si).

Abstract: A technique capable of improving the reliability of a non-volatile memory semiconductor device is provided and, in particular, a technique capable of supplying electricity without fail to a memory gate electrode of split gate transistor is provided. One end of an electricity supply line ESL is arranged over a terminal end TE1 and the other end thereof is arranged over a terminal end TE2, and further, the central portion of the electricity supply line ESL is arranged over a dummy part DMY. That is, the terminal end TE1, the terminal end TE2, and the dummy part DMY have substantially the same height, and therefore, most of the electricity supply line ESL arranged from over the terminal end TE1 to over the terminal end TE2 via the dummy part DMY is formed so as to have the same height.

Abstract: A semiconductor-on-insulator structure includes a buried dielectric layer interposed between a base semiconductor substrate and a surface semiconductor layer. The buried dielectric layer comprises an oxide material that includes a nitrogen gradient that peaks at the interface of the buried dielectric layer with at least one of the base semiconductor substrate and surface semiconductor layer. The interface of the buried dielectric layer with the at least one of the base semiconductor substrate and surface semiconductor layer is abrupt, providing a transition in less than about 5 atomic layer thickness, and having less than about 10 angstroms RMS interfacial roughness. A second dielectric layer comprising an oxide dielectric material absent nitrogen may be located interposed between the buried dielectric layer and the surface semiconductor layer.

Abstract: In device isolation trenches, a first device-isolation insulator film is formed to have recesses thereon and a second device-isolation insulator film is formed in the recesses. The uppermost portions at both ends of the first device-isolation insulator film are located higher than the uppermost portions at both ends of the second device-isolation insulator film.

Abstract: An erasable programmable single-poly nonvolatile memory includes a first PMOS transistor comprising a select gate, a first p-type doped region, and a second p-type doped region, wherein the select gate is connected to a select gate voltage, and the first p-type doped region is connected to a source line voltage; a second PMOS transistor comprising the second p-type doped region, a third p-type doped region, and a floating gate, wherein the third p-type doped region is connected to a bit line voltage; and an erase gate region adjacent to the floating gate, wherein the erase gate region is connected to an erase line voltage.

Abstract: An erasable programmable single-poly nonvolatile memory includes a floating gate transistor having a floating gate, a gate oxide layer under the floating gate, and a channel region; and an erase gate region, wherein the floating gate is extended to and is adjacent to the erase gate region. The gate oxide layer comprises a first portion above the channel region of the floating gate transistor and a second portion above the erase gate region, and a thickness of the first portion of the gate oxide layer is different from a thickness of the second portion of the gate oxide layer.