Abstract: Scaling a charge trap memory device and the article made thereby. In one embodiment, the charge trap memory device includes a substrate having a source region, a drain region, and a channel region electrically connecting the source and drain. A tunnel dielectric layer is disposed above the substrate over the channel region, and a multi-layer charge-trapping region disposed on the tunnel dielectric layer. The multi-layer charge-trapping region includes a first deuterated layer disposed on the tunnel dielectric layer, a first nitride layer disposed on the first deuterated layer and a second nitride layer.

Abstract: A portion of a charge trapping layer adjacent to a select drain gate electrode can be removed employing a differential-rate etch process that provides an accelerated etch rate to a doped portion with respect to an undoped portion. If a silicon nitride layer is employed as the charge trapping layer, then angled ion implantation of boron atoms to an upper portion of the silicon nitride layer can increase the etch rate of the boron-doped portion of the silicon nitride layer in phosphoric acid. The charge trapping layer is etched back such that a remaining portion of the charge trapping layer can be present only at levels of control gate electrodes, and absent at each level of select drain gate electrodes. Threshold voltage shift for the select drain gate electrodes can be eliminated or reduced by removal of the charge trapping layer at each level of the select drain gate electrodes.

Abstract: A semiconductor device includes memory blocks each configured to comprise a pair of channels, each channel including a pipe channel formed in a pipe gate of the memory block and a drain-side channel and a source-side channel coupled to the pipe channel; first slits placed between the memory blocks adjacent to other memory blocks; and a second slit placed between the source-side channel and the drain-side channel of each pair of channels.

Abstract: A memory device comprises a first conductive stripe, a first memory layer, a first conductive pillar, a first dielectric layer and a first conductive plug. The first conductive strip extends along a first direction. The first memory layer extends along a second direction adjacent to and overlapping with the first conductive stripe to define a first memory area thereon. The first conductive pillar extends along the second direction and overlapping with the first memory area. The first dielectric layer extends along the second direction adjacent to the first conductive stripe, the first memory layer and the first conductive pillar. The first conductive plus extends along the second direction and at least overlaps with a portion of the first conductive stripe, wherein the first conductive plus is electrically insulated from the first conductive stripe, the first memory layer and the first conductive pillar by the first dielectric layer.

Abstract: According to one embodiment, the array chip includes a three-dimensionally disposed plurality of memory cells and a memory-side interconnection layer connected to the memory cells. The circuit chip includes a substrate, a control circuit provided on the substrate, and a circuit-side interconnection layer provided on the control circuit and connected to the control circuit. The circuit chip is stuck to the array chip with the circuit-side interconnection layer facing to the memory-side interconnection layer. The bonding metal is provided between the memory-side interconnection layer and the circuit-side interconnection layer. The bonding metal is bonded to the memory-side interconnection layer and the circuit-side interconnection layer.

Abstract: A non-volatile memory device includes a first electrode layer, a second electrode layer adjacent to the first electrode layer, a third electrode layer adjacent to the second electrode layer, a fourth electrode layer adjacent to the third electrode layer, and a channel body extending through the first electrode layer, the second electrode layer, the third electrode layer and the fourth electrode layer in a first direction. The device further includes a circuit electrically connected to the first electrode layer, the second electrode layer, the third electrode layer, the fourth electrode layer, and the channel body. The circuit providing the second electrode layer with a first potential, the third electrode layer with a second potential higher than the first potential, the fourth electrode layer with a third potential between the first potential and the second potential and the channel body with a potential rising in the first direction.

Abstract: Provided is a memory device including a stack structure, a plurality of first cap layers, and a plurality of second cap layers. The stack structure is located on a substrate. The stack structure includes a plurality of first conductive layers and a plurality of dielectric layers. The first conductive layers and the dielectric layers are stacked alternately. The first cap layers are located on sidewalls of the first conductive layers respectively. The second cap layers are located on sidewalls of the dielectric layers respectively.

Abstract: A memory device configurable for independent double gate cells, storing multiple bits per cell, includes multilayer stacks of conductive strips configured as word lines. Active pillars are disposed between pairs of first and second stacks, each active pillar comprising a vertical channel structure extending from an underlying bounded conductive layer, a charge storage layer and an insulating layer. The insulating layer in a frustum of an active pillar contacts a first arcuate edge of a first conductive strip in a layer of the first stack and a second arcuate edge of a second conductive strip in a same layer of the second stack. The conductive strips can comprise a metal. The active pillar can be generally elliptical with a major axis parallel with the first and second conductive strips.

Abstract: A three-dimensional nonvolatile memory device includes a first vertical channel layer and a second vertical channel layer extending from a substrate, a plurality of memory cells, first selection transistors and second selection transistors spaced apart from each other along the first vertical channel layer and the second vertical channel layer, a pad, a contact plug and a bit line in a stacked configuration over the first vertical channel layer, and a common source line formed over the second vertical channel layer.

Abstract: A memory device includes a stack of material layers with a plurality of NAND strings extending through the stack, and a trench through the stack with a pair of sidewalls defining a width of the trench that is substantially constant or decreases from the top of the trench to a first depth and increases between a first depth and a second depth that is closer to the bottom of the trench than the first depth and the trench has an insulating material covering at least the trench sidewalls. Further embodiments include a memory device including a stack of material layers and an active memory cell region defined between a pair of trenches, and within the active region the stack comprises alternating layers of a first material and a second material, and outside of the active region the stack comprises alternating layers of the first material and a third material.

Abstract: Present example embodiments relate generally to methods of fabricating a three-dimensional gate-all-around (GAA) vertical gate (VG) semiconductor structure comprising providing a substrate; forming a plurality of layers having alternating first insulative material layers and second insulative material layers over the substrate; identifying bit line and word line locations for the formation of bit lines and word lines; removing at least a portion of the plurality of layers outside of the identified bit line and word line locations, each of the removed portions extending through the plurality of layers to at least a top surface of the substrate; forming a vertical first insulative material structure in the removed portions; performing an isotropic etching process to remove the second insulative material from the second insulative material layers; forming bit lines in the second insulative material layers within the identified bit line locations; and forming word lines in the identified word line locations.

Abstract: Air gap isolation in non-volatile memory arrays and related fabrication processes are provided. Electrical isolation between adjacent active areas of a substrate can be provided, at least in part, by bit line air gaps that are elongated in a column direction between the active areas. At least one cap is formed over each isolation region, at least partially overlying air to provide an upper endpoint for the corresponding air gap. The caps may be formed at least partially along the sidewalls of adjacent charge storage regions. In various embodiments, selective growth processes are used to form capping strips over the isolation regions to define the air gaps. Word line air gaps that are elongated in a row direction between adjacent rows of storage elements are also provided.

Abstract: A method of fabricating a memory device is provided. The method includes forming a first alternating stack of insulator layers and spacer material layers over a semiconductor substrate, etching the first alternating stack to expose a single crystalline semiconductor material, forming a first epitaxial semiconductor pedestal on the single crystalline semiconductor material, such that the first epitaxial semiconductor pedestal is in epitaxial alignment with the single crystalline semiconductor material, forming an array of memory stack structures through the first alternating stack, and forming at least one semiconductor device over the first epitaxial semiconductor pedestal.

Abstract: According to one embodiment, a semiconductor memory device includes memory units each includes a first transistor, memory cell transistors, and a second transistor serially coupled between first and second ends. A memory cell transistor of each memory unit has its gate electrode coupled to each other. A bit line is coupled to the first ends. First and second drivers output voltage applied to selected and unselected first transistors, respectively. Third and fourth drivers output voltage applied to selected and unselected second transistors, respectively. A selector couples the gate electrode of the first transistor of each memory unit to the first or second driver, and that of the second transistor of each memory unit to the third or fourth driver.

Abstract: Provided is a neuromorphic device including first and second lower electrodes formed on a substrate to be electrically separated, first and second lower insulating film stacks formed at least on respective surfaces of the first and second lower electrodes, first, second, and third doped regions formed at left and right sides of the first and second lower electrodes, first and second semiconductor regions formed on the first and second lower insulating film stacks, an upper insulating film stack formed on the first and second semiconductor regions and the first, second, and third doped regions, and an upper electrode formed on the upper insulating film stack. Accordingly, a specified neuromorphic device can be reconfigured to have arbitrarily inhibitory or excitatory functionality by using the first and second lower electrodes and the lower insulating film stacks including charge storage layers formed on the surfaces of the electrodes.

Abstract: A method for manufacturing a semiconductor device includes the following steps. At first, two gate stack layers are formed on a semiconductor substrate, wherein each of the gate stack layers includes a top surface and two side surfaces. A conductive material layer is deposited to conformally cover the top surface and the two side surfaces of each of the gate stack layers. Then, a cap layer is deposited to conformally cover the conductive material layer. Finally, the cap layer and the conductive material layer above the top surface of each of the gate stack layers are removed to leave the cap layer adjacent to the two side surfaces of each of the gate stack layers and covering a portion of the conductive material layer.

Abstract: A semiconductor device, including gate electrodes perpendicularly stacked on a substrate; channel holes extending perpendicularly to the substrate, the channel holes penetrating through the gate electrodes, the channel holes having a channel region; gate pads extended from the gate electrodes by different lengths; and contact plugs connected to the gate pads, at least a portion of the gate pads having a region having a thickness less than a thickness of the gate electrode connected to the at least a portion of the gate pads.

Abstract: A memory device configurable for independent double gate cells, storing multiple bits per cell includes multilayer stacks of conductive strips configured as word lines. Active pillars are disposed between pairs of first and second stacks, each active pillar comprising a vertical channel structure, a charge storage layer and an insulating layer. The insulating layer in a frustum of an active pillar contacts a first arcuate edge of a first conductive strip in a layer of the first stack and a second arcuate edge of a second conductive strip in a same layer of the second stack. A plurality of insulating columns serve, with the active pillars, to divide the stacks of word lines into even and odd lines contacting opposing even and odd sides of each active pillar. The active pillar can be generally elliptical with a major axis parallel with the first and second conductive strips.

Abstract: A memory device includes a substrate, a first doped region, composite structures, word lines, and a charge storage layer. The first doped region is disposed on a surface of the substrate. The composite structures are disposed on the first doped region. Each composite structure includes two semiconductor fin structures and a dielectric layer. Each semiconductor fin structure includes a second doped region disposed at an upper portion of the semiconductor fin structure and a body region disposed between the second doped region and the first doped region. The dielectric layer is disposed between the semiconductor fin structures. The word lines are disposed on the substrate. Each word line covers a partial sidewall and a partial top of each composite structure. The charge storage layer is disposed between the composite structures and the word lines.

Abstract: According to one embodiment, a memory device, includes: a stacked body including first electrode layers stacked alternately with first insulating layers; a selection gate stacked body including selection gate electrode layers stacked alternately with second insulating layers in a stacking direction of the stacked body; a semiconductor member provided inside the stacked body and the selection gate stacked body, the semiconductor member extending in the stacking direction; a memory film provided between the semiconductor member and each of the f first electrode layers; and a gate insulator film provided between the semiconductor member and each of the selection gate electrode layers. Selection transistors are provided on the stacked body, the plurality of selection transistors included the selection gate electrode layers, the gate insulator film, and the semiconductor member, at least two of the selection transistors have mutually different threshold potentials.

Abstract: A semiconductor memory device includes: a semiconductor region extending vertically from a first region of a substrate; a plurality of gate electrodes disposed on the first region of the substrate in a vertical direction, but separated from each other along a sidewall of the semiconductor region; a gate dielectric layer disposed between the semiconductor region and the plurality of gate electrodes; a substrate contact electrode extending vertically from the impurity-doped second region of the substrate; and an insulating region formed as an air gap between the substrate contact electrode and at least one of the plurality of gate electrodes.

Abstract: This non-volatile semiconductor memory device includes a memory cell array including NAND cell units formed in a first direction vertical to a surface of a semiconductor substrate. A local source line is electrically coupled to one end of the NAND cell unit formed on the surface of the substrate. The memory cell array includes: a laminated body where plural conductive films, which are to be control gate lines of memory cells or selection gate lines of selection transistors, are laminated sandwiching interlayer insulating films; a semiconductor layer that extends in the first direction; and an electric charge accumulating layer sandwiched between: the semiconductor layer and the conductive film. The local source line includes a silicide layer. The electric charge accumulating layer is continuously formed from the memory cell array to cover a peripheral area of the silicide layer.

Abstract: A non-volatile memory device in accordance with one embodiment of the present invention includes a substrate including a P-type impurity-doped region, a channel structure comprising a plurality of interlayer insulating layers that are alternately stacked with a plurality of channel layers on the substrate, a P-type semiconductor pattern that contacts sidewalls of the plurality of channel layers, wherein a lower end of the P-type semiconductor pattern contacts the P-type impurity-doped region, and source lines that are disposed at both sides of the P-type semiconductor pattern and contact the sidewalls of the plurality of channel layers.

Abstract: A nonvolatile memory device includes a pipe insulation layer having a pipe channel hole, a pipe gate disposed over the pipe insulation layer, a pair of cell strings each having a columnar cell channel, and a pipe channel coupling the columnar cell channels and surrounding inner sidewalls and a bottom of the pipe channel hole.

Abstract: A floating gate insulating film is formed in a first element formation region of a substrate. A first insulating film and a control gate electrode are continuously formed from the first element formation region to a first element isolation film. A selection gate insulating film and a selection gate electrode are formed in the substrate located in the first element formation region. The selection gate electrode is continuously formed over the first element isolation film. A side surface of the selection gate electrode is in contact with a first side surface of a floating gate electrode through a second insulating film. An upper surface of a region overlapping with the selection gate electrode in the first element isolation film is located lower than an upper surface of the substrate.

Abstract: Provided is a semiconductor device including a substrate and a stack layer. The substrate includes a first region, a second region, and a third region. The third region is disposed between the first region and the second region. Since a top surface of the substrate in the first region is lower than the top surface of the substrate in the second region, the substrate in the third region has a first step height. The stack layer is disposed on the substrate in the first and third regions. The top surface of the stack layer in the first region and the third region and the top surface of the substrate in the second region are substantially coplanar.

Abstract: A device is disclosed including one or more field effect transistors, each field effect transistor including: an elongated drain contact line including an electrically conductive material extending along a first horizontal direction; a drain including a first conductivity type semiconductor region overlaying the drain contact line; a source including a the first conductivity type semiconductor region located above the drain; and a gate extending vertically between the drain and the source.

Abstract: A three-dimensional nonvolatile memory device includes a first vertical channel layer and a second vertical channel layer extending from a substrate, a plurality of memory cells, first selection transistors and second selection transistors spaced apart from each other along the first vertical channel layer and the second vertical channel layer, a pad, a contact plug and a bit line in a stacked configuration over the first vertical channel layer, and a common source line formed over the second vertical channel layer.

Abstract: A semiconductor device includes a lower insulating pattern on a semiconductor substrate, a lower gate pattern on the lower insulating pattern and formed of a doped polysilicon layer, a residual insulating pattern with an opening exposing a portion of a top surface of the lower gate pattern, an upper gate pattern on the residual insulating pattern, the upper gate pattern filling the opening, and a diffusion barrier pattern in contact with the portion of the top surface of the lower gate pattern and extending between the residual insulating pattern and the upper gate pattern.

Abstract: A three-dimensional semiconductor device and a method of fabricating the same, the device including a lower insulating layer on a top surface of a substrate; an electrode structure sequentially stacked on the lower insulating layer, the electrode structure including conductive patterns; a semiconductor pattern penetrating the electrode structure and the lower insulating layer and being connected to the substrate; and a vertical insulating layer interposed between the semiconductor pattern and the electrode structure, the vertical insulating layer crossing the conductive patterns in a vertical direction and being in contact with a top surface of the lower insulating layer.

Abstract: Systems, methods, and apparatuses are provided to obtain diagnostic information from a storage device. A read command may be transmitted to a storage device, where the read command conforms to a block level storage protocol and is directed to an unused logical unit of storage memory included in the storage device, to an invalid logical block address, and/or to a mode page. The unused logical unit may be a predetermined logical unit of the storage memory that is not allocated by a file system. Diagnostic data may be received from the storage device in response to the read command. The diagnostic data may be information related to operation of the storage device and/or a component of the storage device.

Abstract: An improvement is achieved in the performance of semiconductor device including a nonvolatile memory. In a split-gate nonvolatile memory, between a memory gate electrode and a p-type well and between a control gate electrode and the memory gate electrode, an insulating film is formed. Of the insulating film, the portion between the lower surface of the memory gate electrode and the upper surface of a semiconductor substrate has silicon oxide films, and a silicon nitride film interposed between the silicon oxide films. Of the insulating film, the portion between a side surface of the control gate electrode and a side surface of the memory gate electrode is formed of a silicon oxide film, and does not have the silicon nitride film.

Abstract: A semiconductor device having a structure which can prevent a decrease in electrical characteristics, which becomes more significant with miniaturization of a transistor, is provided. In addition, a highly reliable semiconductor device is provided. The semiconductor device includes a first gate electrode layer, a second gate electrode layer, and a third gate electrode layer, which are each provided separately. The first gate electrode layer overlaps with an oxide semiconductor layer. The second gate electrode layer partly covers one end portion of the oxide semiconductor layer in the channel width direction. The third gate electrode layer partly covers the other end portion of the oxide semiconductor layer in the channel width direction.

Abstract: A hollow-channel memory device comprises a source layer, a first hollow-channel pillar structure formed on the source layer, and a second hollow-channel pillar structure formed on the first hollow-channel pillar structure. The first hollow-channel pillar structure comprises a first thin channel and the second hollow-channel pillar structure comprises a second thin channel that is in contact with the first thin channel. In one exemplary embodiment, the first thin channel comprises a first level of doping; and the second thin channel comprises a second level of doping that is different from the first level of doping. In another exemplary embodiment, the first and second levels of doping are the same.

Abstract: According to an aspect of the invention, a first insulating layer is buried in a first trench provided in at least one of an interstice between first and second semiconductor pillars, a side surface portion of the first semiconductor pillar opposed to the second semiconductor pillar, and a side surface portion of the second semiconductor pillar opposed to the first semiconductor pillar. A first trench penetrates each stack from an uppermost portion of the stack to a first conductive layer in a lowermost portion of the stack. The first trench is arranged away from a first connection portion. Each of the first conductive layers in contact with the first insulating layer includes a silicide layer.

Abstract: A semiconductor device includes a semiconductor substrate having a plurality of isolation regions, a plurality of trenches, where each of the plurality of trenches is formed in a corresponding isolation region, of the plurality of isolation regions, and where the plurality of trenches are arranged, in parallel, along a first direction, a plurality of gate lines formed on the semiconductor substrate in a second direction crossing the plurality of trenches, an insulating layer formed between each of the plurality of gate lines, a first air gap formed in at least one of the plurality of trenches, the first air gap extending in the first direction, and a second air gap formed in at least one of the insulating layers, the second air gap extending in the second direction.

Abstract: A method for use in the manufacture of an electronic circuit comprising at least one substantially planar electronic device is disclosed.

Abstract: Provided are a semiconductor device and a method of fabricating the same. The semiconductor device includes a substrate doped with a first conductive type dopant, a plurality of stacked structures arranged side by side on the substrate and extending in a first direction, each of the stacked structures including gate electrodes spaced apart from each other, the plurality of stacked structures including a pair of stacked structures spaced apart from each other at a first interval in a second direction perpendicular to the first direction, and a pick-up region extending in the first direction in the substrate between the pair of stacked structures and doped with the first conductive type dopant.

Abstract: A semiconductor device includes a trench formed in a substrate, a first stacked structure formed in the trench and including a plurality of first material layers and a plurality of second material layers stacked alternately on top of each other, and a transistor located on the substrate at a height corresponding to a top surface of the first stacked structure.

Abstract: A semiconductor memory device comprises: a semiconductor substrate; a plurality of memory units provided on the semiconductor substrate and each including a plurality of memory cells that are stacked; and a plurality of bit lines formed above each of a plurality of the memory units aligned in a column direction, an alignment pitch in a row direction of the plurality of bit lines being less than an alignment pitch in the row direction of the memory units, and an end of each of the memory units aligned in the column direction being connected to one of the plurality of bit lines formed above the plurality of the memory units aligned in the column direction.

Abstract: A semiconductor device includes a substrate, at least one logic device and a split gate memory device. The at least one logic device is located on the substrate. The split gate memory device is located on the substrate and comprises a memory gate and a select gate. The memory gate and the select gate are adjacent to and electrically isolated with each other. A top of the select gate is higher than a top of the memory gate.

Abstract: To provide a semiconductor device having a nonvolatile memory improved in characteristics. In the semiconductor device, a nonvolatile memory has a high-k insulating film (high dielectric constant film) between a control gate electrode portion and a memory gate electrode portion and a transistor of a peripheral circuit region has a high-k/metal configuration. The high-k insulating film arranged between the control gate electrode portion and the memory gate electrode portion relaxes an electric field intensity at the end portion (corner portion) of the memory gate electrode portion on the side of the control gate electrode portion. This results in reduction in uneven distribution of charges in a charge accumulation portion (silicon nitride film) and improvement in erase accuracy.

Abstract: Integrated circuits are provided. An exemplary integrated circuit includes a source/drain region in a semiconductor substrate. The integrated circuit includes a charge storage structure overlying the semiconductor substrate and having a first sidewall overlying the source/drain region. The integrated circuit also includes a control gate overlying the source/drain region. Further, the integrated circuit includes a first select gate overlying the semiconductor substrate and adjacent the first sidewall. A first memory cell is formed by the control gate and the first select gate.

Abstract: Methods for forming a string of memory cells and apparatuses having a vertical string of memory cells are disclosed. One such string of memory cells can be formed at least partially in a stack of materials comprising a plurality of alternating levels of control gate material and insulator material. A memory cell of the string can include floating gate material adjacent to a level of control gate material of the levels of control gate material. The memory cell can also include tunnel dielectric material adjacent to the floating gate material. The level of control gate material and the tunnel dielectric material are adjacent opposing surfaces of the floating gate material. The memory cell can include metal along an interface between the tunnel dielectric material and the floating gate material. The memory cell can further include a semiconductor material adjacent to the tunnel dielectric material.

Abstract: A semiconductor memory array includes a first nonvolatile memory cell having a first charge storage layer and a first gate electrode and a second nonvolatile memory cell, adjacent to the first memory cell in a first direction, having a second charge storage layer and a second gate electrode. The first and second electrodes extend in a second direction perpendicular to the first direction, the first electrode has a first contact section extending toward the second electrode in the first direction, and the second electrode has a second contact section extending toward the first electrode in the first direction. The first and second contact positions are shifted in the second direction, respectively, and the first electrode and the first contact section are electrically separated from the second electrode and the second contact section.

Abstract: To provide a semiconductor device with nonvolatile memory, having improved performance. A memory cell has control and memory gate electrodes on a semiconductor substrate via an insulating film and another insulating film having first, second, and third films stacked one after another in order of mention, respectively. The memory and control gate electrodes are adjacent to each other via the stacked insulating film. The second insulating film has a charge accumulation function. The first and third insulating films each have a band gap greater than that of the second insulating film. An inner angle of the second insulating film between a portion extending between the semiconductor substrate and the memory gate electrode and a portion extending between the control gate electrode and the memory gate electrode is ?90°. An inner angle of the corner portion between the lower surface and the side surface of the memory gate electrode is <90°.

Abstract: A semiconductor device includes a substrate, at least one split gate memory device, and at least one logic device. The split gate memory device is disposed on the substrate. The logic device is disposed on the substrate. A select gate or a main gate of the split gate memory device and a logic gate of the logic device are both made of metal, and the other gate of the split gate memory device is made of nonmetal.

Abstract: According to one embodiment, the stacked body includes a plurality of electrode layers and a plurality of insulating layers alternately stacked on the substrate. The plurality of contact parts are provided in a protruding shape on respective end parts of the plurality of electrode layers. The plurality of contact parts do not overlap each other in the stacking direction. The plurality of contact parts are displaced in a surface direction of the substrate. The plurality of plugs extends from the respective contact parts toward the respective circuit interconnections and electrically connects the respective contact parts with the respective circuit interconnections.

Abstract: A method of fabricating a semiconductor device, such as a three-dimensional monolithic NAND memory string, includes etching a select gate electrode over a first gate insulating layer over a substrate to form an opening, forming a second gate insulating layer over the sidewalls of the opening, forming a sacrificial spacer layer over the second gate insulating layer on the sidewalls of the opening, and etching the first gate insulating layer over the bottom surface of the opening to expose the substrate, removing the sacrificial spacer layer to expose the second gate insulating layer over the sidewalls of the opening, and forming a protrusion comprising a semiconductor material within the opening and contacting the substrate, wherein the second gate insulating layer is located between the select gate electrode and first and second side surfaces of the protrusion.

Abstract: Monolithic three dimensional NAND strings and methods of making. The method includes both front side and back side processing. Using the combination of front side and back side processing, a NAND string can be formed that includes an air gap between the floating gates in the NAND string. The NAND string may be formed with a single vertical channel. Alternatively, the NAND string may have a U shape with two vertical channels connected with a horizontal channel.