Abstract: A method for interconnecting bit contacts and digit lines of a semiconductor device. A mask, through which portions of sidewall spacers of the digit lines located proximate the bit contacts are exposed, is positioned over the digit lines. Dopant is directed toward the semiconductor device at a non-perpendicular angle to a plane of the semiconductor device so as to dope portions of the sidewall spacers on one side of each of the digit lines while sidewall spacers opposed thereto and adjacent bit contacts are shielded from the dopant. Doped regions of the sidewall spacers may be removed with selectivity over undoped regions thereof to expose connect regions of each conductive element of each digit line. A conductive strap may then be formed to electrically link each connect region to its corresponding bit contact. Semiconductor devices including the conductive straps are also disclosed.

Abstract: A lateral, high-voltage, FET having a low on-resistance and a buried conduction layer comprises a P-type buried layer region within an N-well formed in a P-type substrate. The P-type buried layer region is connected to a drain electrode by a first P-type drain diffusion region that is disposed in the N-well region. The P-type buried layer region is also connected to a second P-type drain diffusion region that extends down from the surface at one end of the PMOS gate region. A P-type source diffusion region, which connects to the source electrode, defines the other end of the gate region.

Abstract: An EEPROM system having an array of memory cells that individually include two floating gates, bit line source and drain diffusions extending along columns, steering gates also extending along columns and select gates forming word lines along rows of floating gates. The dual gate cell increases the density of data that can be stored. Rather than providing a separate steering gate for each column of floating gates, an individual steering gate is shared by two adjacent columns of floating gates that have a diffusion between them. Processing methods of forming such a cell array include two etching steps to separate strips of conductive material into individual floating gates that are self-aligned with source/drain diffusions and other gate elements. In one embodiment, this is accomplished by two etching steps with separate masks.

Abstract: The invention includes buried bit line memory circuitry, methods of forming buried bit line memory circuitry, and semiconductor processing methods of forming conductive lines. In but one implementation, a semiconductor processing method of forming a conductive line includes forming a silicon comprising region over a substrate. A TiNx comprising layer is deposited over the silicon comprising region, where “x” is greater than 0 and less than 1. The TiNx comprising layer is annealed in a nitrogen containing atmosphere effective to transform at least an outermost portion of the TiNx layer over the silicon comprising region to TiN. After the annealing, an elemental tungsten comprising layer is deposited on the TiN and at least the elemental tungsten comprising layer, the TiN, and any remaining TiNx layer is patterned into conductive line. In one implementation, a method such as the above is utilized in the fabrication of buried bit line memory circuitry.

Abstract: A memory array includes a semiconductor substrate, an isolation trench disposed in the substrate, and a conductor that is disposed in the trench. The array also includes a memory cell that is coupled to the conductor in the trench. The conductor may be a digit line that is coupled to a source/drain region of the memory cell or to a shared source/drain region of a pair of adjacent memory cells.

Abstract: The present invention provides a method of forming a diffusion layer which extends on bottoms and side walls of trench grooves as well as on top portions of ridged portions separating the trench grooves, and the trench grooves being separated by ridged portions of the substrate so that the trench grooves and the ridged portions are aligned between adjacent two of gate electrode structures, the method comprising the steps of: carrying out a first ion-implantation in a vertical direction to introduce an impurity into the bottoms of the trench grooves and into top portions of the ridged portions by use of gate electrode structures; forming side wall insulation films on side wails of the gate electrode structures; and carrying out a second ion-implantation in an oblique direction with a rotation of the substrate by use of the gate electrode structures and the side walls.

Abstract: The invention relates to a phase-change memory device. The device includes a double-trench isolation structure around the diode stack that communicates to the lower electrode. The present invention also relates to a method of making a phase-change memory device. The method includes forming two orthogonal and intersecting isolation trenches around a memory cell structure diode stack.

Abstract: A process for fabricating a memory cell in a two-bit EEPROM device including forming an ONO layer overlying a semiconductor substrate, depositing a hard mask overlying the ONO layer, and patterning the hard mask. The hard mask is made from tungsten, titanium, or titanium nitride. The process further includes doping the semiconductor substrate with boron causing p-type regions to form in the semiconductor substrate, and doping the semiconductor substrate with n-type dopants, such as arsenic, causing n-type regions to form in the semiconductor substrate. The exposed ONO layer is then etched to expose part of the semiconductor substrate, and a bit-line oxide region is formed overlying the semiconductor substrate. The hard mask is then stripped, preferably using an H2O2 solution.

Abstract: A fabrication process of a non-volatile semiconductor memory device includes the step of forming a plurality of openings in a device isolation structure defining an active region in a memory cell region such that each opening exposes the substrate surface extends from the active region to the outside thereof. Further, silicide regions are formed in the openings by a self-aligned process such that the silicide regions are mutually separated. Further a contact hole is formed in an interlayer insulation film in correspondence to the silicide regions.

Abstract: In a semiconductor memory device, such as a flash memory device, a conductor layer of metal or metal compound having high refractoriness, such as titanium nitride, is formed on a conductor or wiring formed by a buried diffusion layer to reduce resistance thereof. In the present invention, such conductor layer is formed by using small number of process steps and without using photolithography process. For example, after forming the buried diffusion layer for source and drain regions by ion implantation using each floating gate and dummy gate as a mask, titanium nitride is deposited throughout a substrate. Thereafter, by using oxide film growth and etching back process, an oxide film layer remaining on the titanium nitride layer between the floating gate and the dummy gate is fabricated. Then, the titanium nitride layer on the floating gate and on the dummy gate is removed by using this remained oxide film layer as a mask, without using any photolithography process.

Abstract: A method of forming a floating gate electrode of a cell of a flash memory device having an interval less than a critical dimension (CD) in a conventional photolithographic process, in which the reliability of a dielectric layer does not deteriorate and damage to a floating gate electrode during etching is prevented, is provided. According to the present invention, a protective layer formed of a material having a high etching selectivity with respect to a device isolation layer and a doped polysilicon layer is formed on the upper surface of the doped polysilicon layer forming the floating gate electrode. The protective layer is partially etched and includes a recess. Next, a material layer for forming a spacer, which is formed of a material having a high etching selectivity with respect to the device isolation layer and the doped polysilicon layer, is formed on the upper surface of the protective layer and is etched back, thus forming the spacer.

Abstract: Self-aligned etching process for providing a plurality of mutually parallel word lines in a first conducting layer deposited over a plagiarized architecture obtained starting from a semiconductor substrate on which is provided a plurality of active elements extending along separate parallel lines e.g., memory cell bit lines and comprising gate regions made up of a first conducting layer, an intermediate dielectric layer and a second conducting layer with said regions being insulated from each other by insulation regions to form said architecture with said word lines being defined photolithographically by protective strips implemented by means of: a vertical profile etching for complete removal from the unprotected areas of the first conducting layer of the second conducting layer and of the intermediate dielectric layer respectively, and a following isotropic etching of the first conducting layer.

Abstract: Disclosed is an EEPROM device, and a method of making such a device, which incorporates a self-aligned tunnel window having acceptably low gate capacitance at the tunnel oxide node, and which avoids the defects caused by field oxide induced stresses in the tunnel oxide. The EEPROM of the present invention includes a semiconductor substrate with a doped memory diffusion region. Overlying at least a portion of the memory diffusion is a tunnel oxide. Overlying at least a portion of the tunnel oxide is a floating gate structure including an extension. The tunnel window of the EEPROM of the present invention is defined within at least a portion of the tunnel oxide and having at least two edges defined by the floating gate extension, so that when a defined voltage is applied to the memory diffusion a tunnel current sufficient to change the state of the EEPROM flows between the memory diffusion and the floating gate structure.

Abstract: A process for fabricating a memory cell, the process includes forming an ONO layer overlying a semiconductor substrate, depositing a resist mask overlying the ONO layer, patterning the resist mask, implanting the semiconductor substrate with an n-type dopant, wherein the resist mask is used as an ion implant mask, and etching the resist mask upon implanting the semiconductor substrate with an n-type dopant. In one preferred embodiment, the etching of the resist mask includes performing a blanket anisotropic etch to reduce the thickness of the resist mask and round the edges of the resist mask. Preferably, the blanket anisotropic etch is performed using an etch including an element selected from the group consisting of nitrogen, hydrogen, chlorine, and helium.

Abstract: A new method of forming non-volatile memory cells with an improved bottom silicon dioxide layer of the O—N—O has been achieved. A semiconductor substrate is provided. A tunneling dielectric layer is grown overlying the semiconductor substrate. A polysilicon layer is deposited overlying the tunneling dielectric layer. Nitrogen is implanted into the polysilicon layer to form a nitridized surface region. The polysilicon layer and the tunneling dielectric layer are then patterned to form floating gates. A bottom silicon dioxide layer is grown overlying the floating gates by thermal oxidation of the polysilicon layer. The nitridized surface region reduces the rate of thermal oxidation and creates a smooth surface. A silicon nitride layer is deposited overlying the bottom silicon dioxide layer. A top silicon dioxide layer is formed overlying the silicon nitride layer to complete the O—N—O stack.

Abstract: A method of forming a vertical transistor. A pad layer is formed over a semiconductor substrate. A trough is formed through the pad layer and in the semiconductor substrate. A bit line is formed buried in the trough. The bit line is enclosed by a dielectric material. A strap is formed extending through the dielectric material to connect the bit line to the semiconductor substrate. The trough is filled above the bit line with a conductor. The conductor is cut along its longitudinal axis such that the conductor remains on one side of the trough. Wordline troughs are formed, substantially orthogonal to the bit line, above the semiconductor substrate. A portion of the conductor is removed under the wordline trough to separate the conductor into separate gate conductors. Wordlines are formed in the wordline trough connected to the separate gate conductors.

Abstract: The present invention relates to a method of forming a non-volatile memory device such as an EEPROM device. The non-volatile memory device is formed of an array of memory cells (10) organized into rows (20) and columns (22) within a semiconductor substrate (100). Each cell (10) comprises a gate structure (120) formed of a first dielectric layer (122), a floating gate (124), a second dielectric layer (126) and a control gate (128) formed in a well (50). The memory device further comprises insulating trenches (200) formed in said substrate (100) along a direction parallel to said columns (22) and isolating each cell (10) within a column (22) from other cells (10) within adjacent columns (22).

Abstract: A method for fabricating a non-volatile memory on the semiconductor substrate is disclosed. First of all, a plurality of trench isolation regions are formed. Then, firstly implanting ions of a first conductivity type and second conductivity type are carried out. Secondly implanting ions of the first conductivity type and second conductivity type are carried out. Then, a first oxide layer is deposited and the first oxide layer is removed. A second oxide layer is deposited. A portion of second oxide is removed, thus, a portion of second oxide layer is remained. A third oxide layer is formed. A first polysilicon layer is formed. The first polysilicon layer is etched. A oxide-nitride-oxide layer is formed. Consequentially, the oxide-nitride-oxide layer are all etched. The second polysilicon on is formed. A portion of the second polysilicon layer, a portion of the first polysilicon layer, a portion of the third oxide layer and a portion of the second oxide layer are all etched. Thus, capacitor columns are formed.

Abstract: A fully recessed device structure and method for low power applications comprises a trenched floating gate and a trenched control gate formed in a single trench etched into a well junction region in a semiconductor substrate to provide a substantially planar topography for low power applications. The trenched floating gate is electrically isolated from the trenched control gate by an inter-gate dielectric layer formed inside the trench and on a top surface of the trenched floating gate. The trenched control gate is formed on a top surface of the inter-gate dielectric layer and preferably, has a top surface which is substantially planar with a top surface of the semiconductor substrate. The fully recessed structure further comprises a buried source region, a buried drain region and a channel region. The buried source region and the buried drain region are formed in the well junction region and are laterally separated by the trench.

Abstract: A method of fabricating a nonvolatile memory device having a first conductivity type substrate, includes the steps of forming a gate insulating layer on the entire surface of the semiconductor substrate, forming a plurality of floating gate lines on the gate insulating layer, forming first sidewall spacers on both sides of each floating gate, forming a plurality of impurity regions having a second conductivity type in the substrate between the floating gate lines, forming a dielectric layer on the floating gate lines, forming a plurality of control gate lines on the dielectric layer, forming second sidewall spacers on both sides of the control gate lines, selectively etching the dielectric layer and the floating gate lines to form a plurality of floating gates, forming tunneling insulating layers on both sides of the floating gates, and forming a plurality of program lines between the impurity regions.

Abstract: A method is provided to improve the control of bird's beak profile of poly in a split gate flash memory cell. The control of the bird's beak profile is achieved in a first embodiment where the polycrystalline layer of the floating gate is annealed at a high temperature. The annealing promotes small grain size and hence smoother surface in the polysilicon, which in turn promotes sharper poly tip. The smoother poly surface also results in thinner inter-poly between the floating gate and the control gate, which together with the sharp poly tip, enhances the erase speed of the split-gate flash memory cell. In a second embodiment, the performance is further enhanced by providing an amorphous silicon for the floating gate, because the amorphous nature of the silicon yields a very smooth surface. This smooth surface is transferred to the recrystallized state of the silicon layer through annealing. Thus, a good control for the bird's beak is achieved.

Abstract: A method of interconnecting bit contacts to corresponding digit lines of a semiconductor memory device. The method is particularly useful for fabricating semiconductor memory devices having digit lines that are less than about 0.2 microns wide and spaced less than about 0.2 microns apart from one another. A mask, which shields portions of the digit lines of the semiconductor device, through which portions of the digit lines proximate the bit contacts are exposed, is disposed over the semiconductor device. The mask preferably includes elongated apertures alignable transversely to the digit lines. Dopant is directed toward the semiconductor device at a non-perpendicular angle to a plane of the semiconductor device. Thus, portions of the sidewall spacers of one side of each of the digit lines, sidewall spacers on the opposite sides of the digit lines, or the bit contacts may not be exposed to dopant.

Abstract: A process for fabricating a MONOS Flash cell device having a bit-line includes providing a semiconductor substrate and growing a pad silicon oxide layer overlying the semiconductor substrate. Thereafter, a silicon nitride layer is formed overlying the pad silicon oxide layer. A shallow trench isolation etch is performed to form a trench in the semiconductor substrate. Thereafter, a silicon oxide is deposited to fill the trench. To planarize the silicon oxide to an upper of the silicon nitride layer, a chemical-mechanical-polishing process is performed. Thereafter, the silicon nitride layer and the pad silicon oxide layer are removed, and an oxide-nitride-oxide layer is deposited to overlie the semiconductor substrate.

Abstract: In a semiconductor device, a plurality of transistor elements, each of which is formed by a channel region, a source region, and a drain region, are provided on a substrate, this semiconductor device further having a first element separation region that is made of insulating material and formed by a foot that protrudes form the substrate surface between the transistor elements of a pair of neighboring transistors (6) and (6′) or (6′) and (6″) toward the inside of the substrate and a wing that is connected to the foot (7), and that extends so as to cover the top of either the drain region or the source regions of each of the neighboring transistor elements (6) and (6′).

Abstract: A semiconductor device and a fabrication method thereof which are capable of achieving a lightly doped drain (LDD) construction and reducing a parasitic capacitance generated between an impurity area and a word line by forming a trench in a portion of a semiconductor substrate and forming impurity areas around the trenches, include a semiconductor substrate, a plurality of trenches formed in the semiconductor substrate, first impurity areas formed along the outer surfaces of the plurality of trenches, second impurity areas formed on the bottom surfaces of the first impurity areas along the outer surfaces of the trenches, an insulating film filled in the trenches, a gate insulating film formed at a regular interval on the substrate having the insulating film filled in the trenches, and a gate electrode formed on the gate insulating film.

Abstract: A nonvolatile semiconductor memory cell array is shown which is composed of a plurality of unit cell-arrays arranged in a repeating pattern. Each of the unit cell-arrays includes a first plurality of cell transistors having control gates coupled in common to a first word line and a second plurality of cell transistors having control gates coupled in common to a second word line. The two word lines are arranged in parallel to one another and perpendicular to a bit line. The bit line is connected in common with drains of both the first and second plurality of cell transistors through a bit line contact. A pair of source lines is arranged along each side of the bit line and parallel to the bit line. Each source line is coupled to one transistor from each of the first and second pluralities of cell transistors through a source line contact.

Abstract: A method of forming a semiconductor component having a conductive line (24) that crosses a trench (72). The method involves forming steps (104) in the sidewalls of the trench (72) in a semiconductor substrate (52). A dopant may be implanted at a first energy level into the semiconductor substrate (52) to form a first conductive region (92). The dopant may be implanted at a second energy level into the semiconductor substrate (52) to form a second conductive region (94). The first energy level may be greater than the second energy level. The first conductive region (92) and the second conductive region (94) may form the conductive line (24).

Abstract: A memory array includes a semiconductor substrate, an isolation trench disposed in the substrate, and a conductor that is disposed in the trench. The array also includes a memory cell that is coupled to the conductor in the trench. The conductor may be a digit line that is coupled to a source/drain region of the memory cell or to a shared source/drain region of a pair of adjacent memory cells.

Abstract: The read-only memory takes the form of an integrated circuit. The data stored in the read-only memory include a first data record and a second data record in the form of corresponding first and second structures, respectively, of the integrated circuit. The first structures are fabricated by means of a lithographic projection method with the use of a mask and the second structures are fabricated by means of a lithographic beam writing method without the use of a mask. The invention enables the storage of individual, specialized data for the read-only memory within a primarily mask-programmed ROM.

Abstract: A resist pattern with openings provided at the regions where N+ diffusion layers will be eventually formed is formed on a silicon substrate and thereafter, an N-type impurity is ion-doped to form N+ diffusion layers. Thereafter, gate electrodes are formed via a gate oxide film and then sidewall oxide films are formed, on the semiconductor substrate. Thereafter, an ion implantation of a P-type impurity is performed with a dose two orders of magnitude smaller than that of the N-type impurity for element isolation, with the gate electrodes and the sidewall oxide films being employed as a mask, thereby forming P-type impurity regions. The P-type impurity regions are caused to diffuse due to thermal processing in the following step. However, the element isolating P-type impurity regions resulted from the diffusion diffuse only into immediately under the sidewall oxide films at most, thus preventing the channel width from being narrowed.

Abstract: The invention provides a method for forming a ROM cell surface implant region using a PLDD implant. A semiconductor structure is provided comprising a substrate having isolation structures thereon, which separate and electrically isolating a first area having a P-well formed in the substrate and a gate over the substrate, a second area having a N-well formed in the substrate and a gate over the substrate, and a third area having P-well and buried N+ regions formed in the substrate with second isolation structures overlying the buried N+ regions. A photoresist mask is formed exposing the first area, and impurity ions are implanted to form n-type lightly doped source and drain regions. The photoresist mask is removed and a new (PLDD/ROM) photoresist mask is formed exposing the second area and the third area. Impurity ions are implanted to simultaneously form p-type lightly doped source and drain regions and a ROM cell surface implant region region. The PLDD/ROM photoresist mask is then removed.

Abstract: A method of fabricating a flash memory integrated circuit is described. In an embodiment of the present invention a dielectric filled trench isolation region is formed in a silicon substrate. The dielectric filled trench isolation region isolates a first portion of the silicon substrate from a second portion of the silicon substrate. A portion of the dielectric in the trench is then removed to reveal a portion of the silicon substrate in the trench between the first and second portions of the silicon substrate. Ions are then implanted to form a first source region in the first portion of the silicon substrate and to form a second source region in the second portion of the silicon substrate and to form a doped region in the revealed silicon substrate in the trench wherein the doped region in the trench extends from the first doped source region to the second doped source region.

Abstract: A process for fabricating an MNOS device includes the steps of forming a hardmask containing at least first and second openings over a core array area of a semiconductor substrate. An angle doping process is carried out to form halo regions in precise locations within the substrate at the edges of the first and second openings in the hardmask. Another doping process is carried out to form buried bit-lines in the substrate using the hardmask as a doping mask. Once the halo regions and the buried bit-lines are formed, the hardmask is removed and a composite dielectric layer is formed overlying the substrate.

Abstract: A gate oxide film formed on the surface of a silicon substrate is partly reduced in thickness or “thinned” at its specified part overlying a source region. In a gate region, a multilayer structure is formed which includes a first polycrystalline silicon or “polysilicon” film of a p-type conductivity, a tunnel oxide film, and a second p-type polysilicon film in this order of lamination. The source region and the first polysilicon film make up a high-concentration impurity-doped pn junction with a thin silicon oxide film laid therebetween, providing a tunnel diode also known as Esaki diode. The diode is used for a negative differential resistance. Further, a portion between the first and second polysilicon films is a non-linear tunnel resistor, which serves as a load.

Abstract: A predetermined species such as nitrogen is placed at an interface between a bit line junction and a dielectric layer of a control dielectric structure of a flash memory device to minimize degradation of such an interface by minimizing formation of interface defects during program or erase operations of the flash memory device. The predetermined species such as nitrogen is implanted into a bit line junction of the flash memory device. A thermal process is performed that heats up the semiconductor wafer such that the predetermined species such as nitrogen implanted within the semiconductor wafer thermally drifts to the interface between the bit line junction and the control dielectric structure during the thermal process. The predetermined species such as nitrogen at the interface minimizes formation of interface defects and thus degradation of the interface with time during the program or erase operations of the flash memory device.

Abstract: In a semiconductor device, a pair of diffusion regions are placed in a silicon substrate. Herein, the diffusion regions serve as source and drain regions. Further, a gate oxide film is formed between the diffusion layers or regions and on the silicon substrate. Moreover, a gate electrode is placed on the gate oxide film. In addition, a diamond-like carbon layer is formed over the silicon substrate so as to cover at least the gate oxide film. With such a structure, the diamond-like carbon layer prevents water from diffusing into the gate oxide film.

Abstract: A method of forming a semiconductor component having a conductive line (24) that crosses a trench (72) may include forming the trench (72) in a semiconductor substrate (52). A dopant may be implanted at a first energy level into the semiconductor substrate (52) to form a first conductive region (92). The dopant may be implanted at a second energy level into the semiconductor substrate (52) to form a second conductive region (94). The first energy level may be greater than the second energy level. The first conductive region (92) and the second conductive region (94) may form the conductive line (24).

Abstract: A semiconductor device in which polysilicon is used to form source and drain regions in an initial process step so as to reduce resistance of bit lines and minimize a junction capacitance and thus improve its reliability, and a method for fabricating the same are disclosed, the semiconductor device including a semiconductor substrate, trenches formed in predetermined areas of the semiconductor substrate, an insualting layer formed in the trenches and beneath a surface of the substrate to have a recess, a polysilicon layer formed on the insualting layer in the trench, source and drain regions formed at both sides of the polysilicon layer beneath a surface of the semiconductor substrate, and gates formed over the semiconductor substrate.

Abstract: In this invention a process for a flash memory cell and an architecture for using the flash memory cell is disclosed to provide a nonvolatile memory having a high storage density. Adjacent columns of cells share the same source and the source line connecting these sources runs vertically in the memory layout, connecting to the sources of adjacent columns memory cells. Bit lines connect to drains of cells in adjacent columns and are laid out vertically, alternating with source lines in an every other column scheme. Wordlines made of a second layer of polysilicon form control gates of the flash memory cells and are continuous over the full width of a memory partition. Programming is done in a vertical page using hot electrons to inject charge onto the floating gates. the cells are erased using Fowler-Nordheim tunneling of electrons from the floating gate to the control gate by way of inter polysilicon oxide formed on the walls of the floating gates.

Abstract: A method for manufacturing a bit line and a bit line contact. A semiconductor substrate having a word line thereon is provided. Oxide spacers are formed on the sidewalls of the word line. A dielectric layer that covers the word line is formed over the entire substrate. A cap layer is next formed over the dielectric layer. The cap layer and the dielectric layer are patterned to form a trench in the dielectric layer. Silicon nitride spacers are formed on the sidewalls of the trench. In the subsequent step, the dielectric layer is etched down the trench to form a contact window that exposes a portion of the substrate. Polysilicon material is deposited into the contact window to form a polysilicon plug, and then metal silicide material is deposited into the trench above the plug to form a metal silicide layer.

Abstract: A process for fabricating a MONOS device having a buried bit-line includes providing a semiconductor substrate and forming an ONO structure to overlie the semiconductor substrate. Thereafter, a thin mask layer is formed to overlie the ONO structure to protect the ONO structure during a selective etch of a thick mask layer. The thick mask layer is formed to overlie the thin mask layer to protect the ONO structure during boron and arsenic implants. Thereafter, an etch process is performed in the ONO structure and a silicon oxide layer is formed to fill the etched area. A chemical-mechanical-polishing process is performed to planarize the silicon oxide layer and to form a planar surface continuous with an upper surface of the thick mask layer. The planarized silicon oxide layer functions as a bit-line oxide layer.

Abstract: A process for fabricating a MONOS device having a buried bit-line includes providing a semiconductor substrate and forming an ONO structure overlying the semiconductor substrate. Thereafter, a hard mask layer is formed to overlie ONO structure, the hard mask layer having an upper surface. To form a trench for the buried bit-line, an etch process is performed on the ONO structure. Thereafter, silicon dioxide is deposited to fill the trench. To control a thickness of the deposited silicon dioxide, a chemical-mechanical-polishing process is performed to planarize the silicon dioxide and form a planar surface continuous with the upper surface of the hard mask layer. Finally, the hard mask layer is removed and the remaining silicon dioxide forms a uniform bit-line oxide layer.

Abstract: The present invention relates generally to semiconductor memory devices and more particularly to multi-bit flash electrically erasable programmable read only memory (EEPROM) devices that employ charge trapping within a floating gate to indicate a 0 or 1 bit state. A memory device is provided, according to an aspect of the invention, comprising a floating gate transistor having dual polysilicon floating gates with an isolation opening between floating gates. Processes for making the memory device according to the invention are also disclosed.

Abstract: The present invention relates to a method of manufacturing a MOS transistor, including the steps of delimiting, using a first resist mask N-type, drain and source implantation areas; removing the first mask and diffusing the implanted dopant; annealing, so that a thicker oxide forms above the source and drain regions than above the central gate insulation area; forming a polysilicon finger above the central gate insulation portion to form the gate of the MOS transistor; and performing a second source/drain implantation.

Abstract: In a non-volatile semiconductor memory having a peripheral circuit zone and a memory zone including a number of memory cells each having a floating gate and a control gate, an interlayer insulator film is formed to cover the control gate of the memory cells in the memory zone and a gate electrode formed in the peripheral circuit zone. A contact hole is formed through the interlayer insulator film to reach the gate electrode formed in the peripheral circuit zone, and is filled with a first conducting material. A groove is formed in the interlayer insulator film to longitudinally extend along a word line which constitutes the control gate of a plurality of memory cells arranged in one line. This groove penetrates through the interlayer insulator film to reach the word line over the whole length of the word line.

Abstract: A method of forming flash memory. The method includes forming buried bit lines before the production of shallow trench isolation (STI) structures. The steps for producing the STI structures include forming a pad oxide layer and a silicon nitride layer. A plurality of openings that expose the pad oxide layer is formed in the silicon nitride layer. These openings are located directly above the buried bit lines. Silicon dioxide is deposited to form a silicon dioxide layer that fills these openings. The silicon dioxide layer is capable of preventing the buried bit lines from being cut into segments in subsequent trench-isolation operations.

Abstract: A method of fabricating a flash memory is provided. The flash memory structure is formed with buried bit lines that are lower in resistance, are shallower in buried depth into the substrate, and have a larger punchthrough margin than the prior art. The flash memory structure is constructed on a semiconductor substrate. A tunneling oxide layer is formed over the substrate. A plurality of floating gates is formed at predefined locations over the tunneling oxide layer. A plurality of sidewall spacers is formed on the sidewalls of the floating gates. A plurality of selective polysilicon blocks is formed over the substrate, each being formed between one neighboring pair of the floating gates. An ion-implantation process is performed to dope an impurity element through these selective polysilicon blocks into the substrate to thereby form a plurality of impurity-doped regions in the substrate to serve as a plurality of buried bit line for the flash memory device.

Abstract: An electrically programmable read only memory device which has efficiency of electron injection from channel to floating gate is provided. This memory cell includes a control gate and floating gate between source and drain regions. The region under the floating gate has extremely small enhanced mode channel and N region. Therefore, this channel is completely depleted by the program drain voltage. The enhanced mode channel region is precisely defined by the side wall spacer technique. Also, the N drain region is accurately defined by the difference of side wall polysilicon gate and the first spacer.

Abstract: A three-dimensional, deep-trench, high-density ROM and its manufacturing method are provided. The ROM device comprises a silicon substrate having a plurality of parallel trenches above it surface, wherein, between every two adjacent trenches, there is a higher region. During programming of the ROM device, deeper trenches are formed to define the OFF-state non-conducting memory cells, so that misalignment problems that lead to transistor cell leakage are prevented. The ROM device provides reduced breakdown of the source/drain regions as well.

Abstract: A memory cell having an asymmetric source and drain connection to virtual ground bit-lines providing an abrupt junction suitable for band-to-band hot electron generation and a gradual junction suitable for Fowler-Nordheim tunneling on each side of the cells. A nonvolatile semiconductor memory device comprising row and column arrangement of the cells in which adjacent columns of cells share a single virtual ground bit line.