Abstract: Disclosed are devices and associated methods for manufacturing an EEPROM memory cell (10) for use on a negatively biased substrate (12). The invention may be practiced using standard semiconductor processing techniques. Devices and methods are disclosed for a floating gate transistor for use as an EEPROM cell (10) including a DNwell (14) formed on a P-type substrate (12) for isolating the EEPROM cell (10) from the underlying P-type substrate (12).

Abstract: Non-volatile memory devices according to embodiments of the invention can include, for example, a semiconductor substrate, a source region, a drain region, an impurity region, a vertical structure, a control gate insulating layer, a control gate electrode, a gate insulating layer, and a gate electrode. The impurity region is in a floating state between the source region and the drain region. The vertical structure is formed of a tunneling layer, a charge trapping layer, and a blocking layer sequentially stacked between the source region and the impurity region. The control gate insulating layer is between the source region and the impurity region and adjacent to the vertical structure. The control gate electrode is formed on the vertical structure and the control gate insulating layer. The gate insulating layer is between the impurity region and the drain region. The gate electrode is formed on the gate insulating layer.

Abstract: Within a stacked gate field effect transistor (FET) device, as well as a method for fabrication thereof and a method for operation thereof, there is provided a stacked gate field effect transistor (FET) device comprising a layered stack of a tunneling dielectric layer, a floating gate electrode, an inter-gate electrode dielectric layer and a control gate electrode formed upon a semiconductor substrate. To enhance performance of the stacked gate field effect transistor (FET) device, at least one of: (1) the floating gate electrode is formed with a pointed edge tip at its outer sidewall; (2) the floating gate electrode in formed with a pointed linear recess centered within its linewidth; and (3) a pair of source/drain regions is formed asymmetrically penetrating beneath the pair of opposite edges of the floating gate electrode and not laterally spaced from a floating gate electrode sidewall.

Abstract: A programmable memory transistor (PMT) comprising an IGFET and a coupling capacitor in a semiconductor substrate. The IGFET comprises source and drain regions, a channel therebetween, a gate insulator overlying the channel, and a first floating gate over the gate insulator. The capacitor comprises a lightly-doped well of a first conductivity type, heavily-doped contact and injecting diffusions of opposite conductivity types in the lightly-doped well, a control gate insulator overlying a surface region of the lightly-doped well between the contact and injecting diffusions, a second floating gate on the control gate insulator, and a conductor contacting the lightly-doped well through the contact and injecting diffusions. The first and second floating gates are preferably patterned from a single polysilicon layer, such that the second floating gate is capacitively coupled to the lightly-doped well, and the latter defines a control gate for the first floating gate.

Abstract: The memory cell is formed in a body of a P-type semiconductor material forming a channel region and housing N-type drain and source regions at two opposite sides of the channel region. A floating gate region extends above the channel region. A P-type charge injection region extends in the body contiguously to the drain region, at least in part between the channel region and the drain region. An N-type base region extends between the drain region, the charge injection region, and the channel region. The charge injection region and the drain region are biased by special contact regions so as to forward bias the PN junction formed by the charge injection region and the base region. The holes thus generated in the charge injection region are directly injected through the base region into the body, where they generate, by impact, electrons that are injected towards the floating gate region.

Abstract: A method for operating a P-channel SONOS memory device that has a charge trapping layer located on a substrate, a gate electrode located on the trapping layer, two doped regions located in the substrate at each side of the charge trapping layer. The two doped regions are set to be a drain region and a source region. When a programming action is intended, the gate electrode and the drain region are applied with a first negative high-level bias, and the source region and the substrate are applied with a grounded voltage. When an erasing action is intended, the gate electrode is a second negative bias which is smaller than the first negative voltage in absolute value. In the mean time, the drain region is applied with the third negative bias and the substrate is applied with a grounded voltage. The third negative voltage is larger than the second negative bias in absolute value.

Abstract: One aspect of the invention relates to a virtual ground array floating gate flash memory device with salicided buried bit lines. The bit lines are implanted and salicided after formation of memory cell stacks, but before formation of word lines. The salicide can form over control gates for the memory cells and can contact a third poly layer from which the word lines are patterned. According to another aspect of the invention, an interpoly dielectric coats the sides of the floating gates and significantly improves the capacitance between the floating gate and the memory cell channel. The present invention provides very compact and reliable non-volatile memory.

Abstract: A non-volatile storage cell manufactured in a standard CMOS process in silicon on insulator is described. The cell is manufactured in a standard single polysilicon layer CMOS process applied to silicon on insulator starting substrates. Two versions of the cell are described with distinct mechanisms for writing onto a floating polysilicon layer storage node. The basic cell comprises crossed N- and P- transistors which share a common channel region and a common floating gate over the channel. Current in the channel results in charge injection through the gate oxide and onto the polysilicon gate conductor where it is permanently stored. Since both N and P type transistors are available, charge of both polarities can be injected. Application of a voltage to either of the transistors results in a current or voltage which is used to perform the reading function. Multiple variations of the cell and its operation are also described along with unique applications of the cell.

Abstract: A process for fabrication of a semiconductor device including a modified ONO structure, including forming the modified ONO structure by providing a semiconductor substrate; forming a first oxide layer on the semiconductor substrate; depositing a layer comprising a high-K dielectric material on the first oxide layer; and forming a top oxide layer on the layer comprising a high-K dielectric material. The semiconductor device may be, e.g., a MIRRORBIT™ two-bit EEPROM device or a floating gate flash device including a modified ONO structure.

Abstract: Structures and methods for write once read only memory employing floating gates are provided. The write once read only memory cell includes a floating gate transistor formed in a modified dynamic random access memory (DRAM) fabrication process. The floating gate transistor has a first source/drain region, a second source/drain region, a channel region between the first and the second source/drain regions, a large work function floating gate separated from the channel region by a gate insulator, and a control gate is separated from the floating gate by a gate dielectric. A plug is coupled to the first source/drain region and couples the first source/drain region to an array plate. A transmission line is coupled to the second source/drain region. The floating gate transistor can be programmed in two directions to trap charge in the high work function floating gate.

Abstract: A gate insulating film is formed in a partial area of the surface of a semiconductor substrate, and on this gate insulating film, a gate electrode is formed. An ONO film is formed on the side wall of the gate electrode and on the surface of the semiconductor substrate on both sides of the gate electrode, conformable to the side wall and the surface. A silicon nitride film of the ONO film traps carriers. A conductive side wall spacer faces the side wall of the gate electrode and the surface of the semiconductor substrate via the ONO film. A conductive connection member electrically connects the side wall spacer and gate electrode. Source and drain regions are formed in the surface layer of the semiconductor substrate in areas sandwiching the gate electrode. A semiconductor device is provided which can store data of two bits in one memory cell and can be driven at a low voltage.

Abstract: A method and system for insulating a lower layer of a semiconductor device from an upper layer of the semiconductor device is disclosed. The method and system include providing an interlayer dielectric on the lower layer. The interlayer dielectric is capable of gap filling while using only species of relatively low mobility. The method and system also include planarizing a surface of the interlayer dielectric.

Abstract: A NAND stack array (95′) is placed within a well formed on a semiconductor substrate and includes a series array of memory cell transistors (10) whose threshold voltages can be electrically altered over a range of depletion values. When a cell within a certain NAND stack is selected for a read operation, a peripheral circuit drives selected gate word line to the well potential and drives the word lines of the other gates within the selected NAND stack to a potential at least equal in magnitude to the magnitude of the a reference voltage plus the threshold voltage of a memory cell in the programmed state.

Abstract: The scalable multi-bit flash memory cell includes three regions: the first-side region, the gate region, and the second-side region, in which the gate region includes two stack-gate transistors and one select-gate transistor. The first-side/second-side region comprises a sidewall-oxide spacer formed over the gate region and from top to bottom comprises a planarized thick-oxide layer, a silicided conductive layer formed on a flat bed, and a common-diffusion region. The stack-gate transistor comprises from top to bottom a sidewall dielectric spacer, an elongated control-gate layer formed over an intergate dielectric layer, and an integrated floating-gate layer. The select-gate transistor comprises a planarized conductive island formed over a gate-dielectric layer and is connected to a word line. A plurality of scalable multi-bit flash memory cells are alternately arranged to form a scalable multi-bit flash memory cell array.

Abstract: A method of manufacturing a bipolar transistor in a P-type substrate, including the steps of forming in the substrate a first N-type area; forming by epitaxy a first silicon layer; forming in this first layer, and substantially above the first area a second heavily-doped P-type area separate from the second area; forming at the periphery of this second area a third N-type area; forming by epitaxy a second silicon layer; forming a deep trench crossing the first and second silicon layers, penetrating into the substrate and laterally separating the second area from the third area; and performing an anneal such that the dopant of the third area is in continuity with that of the first area.

Abstract: Within a stacked gate field effect transistor (FET) device, as well as a method for fabrication thereof and a method for operation thereof, there is provided a stacked gate field effect transistor (FET) device comprising a layered stack of a tunneling dielectric layer, a floating gate electrode, an inter-gate electrode dielectric layer and a control gate electrode formed upon a semiconductor substrate. To enhance performance of the stacked gate field effect transistor (FET) device, at least one of: (1) the floating gate electrode is formed with a pointed edge tip at its outer sidewall; (2) the floating gate electrode in formed with a pointed linear recess centered within its linewidth; and (3) a pair of source/drain regions is formed asymmetrically penetrating beneath the pair of opposite edges of the floating gate electrode and not laterally spaced from a floating gate electrode sidewall.

Abstract: The present invention is directed to an integrated circuit having an optimized gate coupling capacitance. The integrated circuit includes a substrate defining a trench therein. A first conductive layer has a portion which extends into the trench. The first conductive layer defines a channel fabricated by a blanket etching step. An insulative layer is adjacent the first conductive layer. A second conductive layer is adjacent the insulative layer. The present invention is further directed to a method of fabricating an integrated circuit. The method includes forming a trench in the substrate, filling the trench with a trench fill material, etching the trench fill material until an upper surface of the trench fill material is below an upper surface of the substrate, providing a first conductive layer over at least a portion of the trench fill material, and blanket etching the first conductive layer until the portion is exposed.

Abstract: A semiconductor memory device and method for making the same, where a memory cell and high voltage MOS transistor are formed on the same substrate. An insulating layer is formed having a first portion that insulates the control and floating gates of the memory cell from each other, and a second portion that insulates the poly gate from the substrate in the MOS transistor. The insulating layer is formed so that its first portion has a smaller thickness than that of its second portion.

Abstract: A self aligned method of forming a semiconductor memory array of floating gate memory cells in a semiconductor substrate, along with strap regions interlaced within the array. The array includes word lines and source lines that connect together control gates and source regions from memory cells contained in row within the array. The strap regions include word line strap cells through which the word lines traverse, wherein the word lines completely traverse across the strap regions, and source line strap cells in which the source lines terminate without completely traversing across the strap region. A first plurality of conductive metal contacts are each connected to one of the word lines in one of the word line strap cells. A second plurality of conductive metal contacts are each connected to one of the source lines in one of the source line strap cells.

Abstract: A high-voltage transistor with a low specific on-state resistance and that supports high voltage in the off-state includes one or more source regions disposed adjacent to a multi-layered extended drain structure which comprises extended drift regions separated from field plate members by one or more dielectric layers. With the field plate members at the lowest circuit potential, the transistor supports high voltages applied to the drain in the off-state. The layered structure may be fabricated in a variety of orientations. A MOSFET structure may be incorporated into the device adjacent to the source region, or, alternatively, the MOSFET structure may be omitted to produce a high-voltage transistor structure having a stand-alone drift region.

Abstract: A high-voltage transistor with a low specific on-state resistance and that supports high voltage in the off-state includes one or more source regions disposed adjacent to a multi-layered extended drain structure which comprises extended drift regions separated from field plate members by one or more dielectric layers. With the field plate members at the lowest circuit potential, the transistor supports high voltages applied to the drain in the off-state. The layered structure may be fabricated in a variety of orientations. A MOSFET structure may be incorporated into the device adjacent to the source region, or, alternatively, the MOSFET structure may be omitted to produce a high-voltage transistor structure having a stand-alone drift region.

Abstract: The present invention provides an ESD apparatus that includes an electrical overstress suppression device in series with a capacitor. The ESD apparatus is ideally suited for use with network communication devices, but any electronic device requiring overvoltage protection and isolation may employ the ESD apparatus of the present invention. In one embodiment, the ESD apparatus includes a capacitor and an electrical overstress protection device that electrically communicates in series with the capacitor. In another embodiment, the ESD apparatus includes an electrical overstress protection device having a voltage variable material and a capacitor that electrically communicates in series with the overstress protection device. The capacitor is sized so that the overstress device can withstand an application of a predetermined steady state voltage.

Abstract: An apparatus having a circuit coupled to the gate contact of a field effect transistor wherein the transistor's gate includes a dielectric layer of which at least a portion is an organic dielectric. The circuit is configured to produce one or more storage voltage pulses that cause charge to be stored in the gate. The field effect transistor has a semiconductor layer with a conductive path whose conductivity changes for a given Vg in response to storing the charge. The circuit may produce one or more dissipation voltage pulses having a voltage of opposite sign to the one or more storage pulses, that cause dissipation of charge stored in the gate. Further disclosed are a memory and a method of electronically storing and reading information, both utilizing the organic-based polarizable gate transistor apparatus.

Abstract: A tunneling charge injector includes a conducting injector electrode, a grid insulator disposed adjacent the conducting injector electrode, a grid electrode disposed adjacent the grid insulator, a retention insulator disposed adjacent the grid electrode, and a floating gate electrode disposed adjacent the retention insulator. In the tunneling charge injector, charge is injected from the conducting injector electrode onto the floating gate. Electrons are injected onto the floating gate when the conducting injector electrode is negatively biased with respect to the grid electrode, and holes are injected onto the floating gate when the conducting injector electrode is positively biased with respect to the grid electrode. The tunneling charge injector is employed in a nonvolatile memory cell having a nonvolatile memory element with a floating gate such as a floating gate MOS transistor.

Abstract: A charge trapping structure for use with an n-channel metal-insulator-semiconductor field-effect transistor (MISFET) is disclosed. A dielectric layer is formed close to a channel region of the MISFET, and includes a number of trapping sites which are arranged and have a concentration sufficient to temporarily store energetic electrons induced by an electric field to move from the channel into the trapping sites. The trapped electrons set up a counter field that depletes the channel of carriers, and as a bias voltage across the channel increases, the device exhibits negative differential resistance (NDR). The charge trapping structure, as well as the rest of the device, are formed using conventional CMOS processing techniques.

Abstract: A nonvolatile semiconductor memory device includes a semiconductor substrate having a main surface, a floating gate electrode having a doped polycrystalline silicon film formed on the main surface with a thermal oxide film therebetween, and a doped polycrystalline silicon film laid over the doped polycrystalline silicon film and having an upward wall, an insulating film covering the doped polycrystalline silicon film, and a control gate electrode formed on the insulating film.

Abstract: A double-bit non-volatile memory structure and a method of forming the structure. The main body of the structure is an array of double-bit memory cells partitioned out by mutually crossing isolation lines and bit lines. Each memory cell includes a pair of stacked gate structures, a doped region in between the stacked gate structures and a pair of common source/drain regions for the pair of stacked gate structures. Each control gate within the pair of stacked gate structures connects electrically with a neighboring word line and each source/drain region connects electrically with a bit line. To form the structure, a plurality of isolation lines is formed over a substrate and then a plurality of linear multi-layered structures perpendicular to the isolation lines are formed over the isolation lines. A pair of neighboring linear multi-layered structures forms a grid unit. Thereafter, source/drain regions and bit lines are formed between various grid units.

Abstract: A flash memory device is configured to address the problems that charges generated when via hole is etched is charged to a junction region through a metal line and are thus concentrated on a tunnel oxide film, thus making distribution of a threshold voltage over a cell uneven when a device is driven. In order to solve the problems, the device has a junction region in an outside circuit region so charges generated when via hole is etched is concentrated on the junction region formed in the outside circuit region. Thus, it can prevent concentration of the charges on the cell and thus make uniform distribution of the threshold voltage over a cell array.

Abstract: When a control gate electrode is processed using a control gate electrode processing mask, the control gate electrode in a region where the floating gate electrode has been removed is partially left. Because of the presence of the left control gate electrode, the gate electrode interlayer insulating film and gate insulating film below the control gate electrode are not dug in the region where the floating gate electrode has been removed. Therefore, when the floating gate electrode is removed, the semiconductor substrate is not dug. In this way, since the semiconductor substrate is not dug, the semiconductor memory device can be manufactured stably and precisely.

Abstract: A scaled stack-gate non-volatile semiconductor memory device having atapered floating-gate structure is disclosed by the present invention, in which a stack-gate structure including a masking dielectric layer over a control-gate layer over an intergate dielectric layer over a tapered floating-gate layer on a thin tunneling-dielectric layer is formed on a semiconductor substrate having an active region isolated by field-oxides and is oxidized. A deeper double-diffused source region having a graded doping profile formed near a gate edge and a shallow drain diffusion region are formed as the first embodiment of the present invention. The deeper double-diffused source and drain regions having a graded doping profile formed near two gate edges are formed as the second embodiment of the present invention. The shallower double-diffused source and drain regions having a graded doping profile formed near two gate edges are formed as the third embodiment of the present invention.

Abstract: A stack-gate structure including a masking dielectric layer over a control-gate layer over an intergate dielectric layer over a floating-gate layer formed on a gate-dielectric layer is formed on a semiconductor substrate having an active region isolated by field-oxides and is oxidized to form a first dielectric layer over the sidewalls of the control-gate layer, a second dielectric layer over the sidewalls of the floating-gate layer, and a thicker oxide layer over each side portion of the active region having a gradedoxide layer formed near two gate edges. An integrated source/drain landing island having a portion formed over a source/drain diffusion region for contact and an extended portion formed over a second dielectric layer and on a graded-oxide layer is acted as a field-emission cathode/anode. The scaled stack-gate flash memory device of the present invention can be programmed and erased through two-tunneling paths or one tunneling path without involving the channel region.

Abstract: Increased write and erase tunnelling currents are developed by enhancement of an electric field near a floating gate with a shaped edge structure overlapping a source/drain diffusion and developing increased floating gate area with angled regions joined by edges in order to reduce write and erase cycle times. The edge structure is formed by selective and preferential etching in accordance with the crystal structure of a monocrystalline semiconductor substrate. The sharpness of the edges and concentration of the electric field may be enhanced by consumption and stress effects of oxidation of the substrate to form a floating gate insulator.

Abstract: The nonvolatile semiconductor memory device has a floating gate electrode that is formed on the semiconductor region and stores carriers injected from the semiconductor region and a control gate electrode that controls the quantity of stored carriers by applying a predetermined voltage to the floating gate electrode. The source region is formed in the semiconductor region on one of side regions of the floating gate electrode and control gate electrode, while the drain region is formed on the other of the side regions thereof. The drain region creates an electric field from which the carriers injected into the floating gate electrode are subject to an external force having an element directed from the semiconductor region to the floating gate electrode.

Abstract: A flash EPROM array (100) and method of manufacture is disclosed. Source regions (118a-118f) are shared between the memory cells (108a,l-108d,n) of row (104a-104d) pairs, and are isolated from one another in the row direction by isolation regions 120. Low resistance source conductor members (122a-122b) extend in the row direction and are formed over the source regions (118a-118f) and make contact therewith in a self-aligned fashion. The architecture allows for source decoding and thus enables user programmable sector erase architecture.

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 power field effect transistor includes a bulge portion and/or a constricted portion in at least one of the heavily doped drain contact region and the lightly doped channel forming region, and heavily doped source regions are formed in the lightly doped channel forming region at intervals, wherein the avalanche breakdown takes place at the bulge portion and/or the constricted portion due to the concentration of electric field in the presence of excess voltage applied to the heavily doped drain contact region, and the breakdown current flows through the gaps between the heavily doped source regions so that a emitter-base junction of a parasitic bipolar transistor is not strongly biased.

Abstract: The present invention provides a flash memory having a split gate structure and a virtual array structure, wherein a high impurity concentration region of a first conductivity type is provided in a drain adjacent region of a channel region under a floating gate electrode, and the high impurity concentration region has a highest impurity concentration in the channel region, and wherein a low impurity concentration region of a first conductivity type is provided in the channel region but at a part not covered by the floating gate.

Abstract: A trench-gated power MOSFET contains a highly doped region in the body region which forms a PN junction diode with the drain at the center of the MOSFET cell. This diode has an avalanche breakdown voltage which is lower than the breakdown voltage of the drain-body junction near to the wall of the trench. Thus the MOSFET breaks down in the center of the cell avoiding the generation of hot carriers that could damage the gate oxide layer. The drain-body junction is located at a level which is above the bottom of the trench, thereby avoiding any deep diffusion that would increase the cell width and reduce the cell packing density. This compact structure is achieved by limiting the thermal budget to which the device is exposed after the body region is implanted. As a result, the body and its highly doped region do not diffuse significantly, and dopant from the highly doped region does not get into the channel region of the device so as to increase its threshold voltage.

Abstract: A semiconductor device as a nonvolatile memory comprises dot elements which are formed out of the semiconductor or conductor fine particles and function as a floating gate. The dot elements are asymmetrically formed to a control gate and may be formed in a sidewall insulating film formed over the side face of the control gate or a select gate. When inclined or stepped portions having level differences are formed in a semiconductor substrate, the dot elements are formed on a specified portion of the inclined or stepped portions.

Abstract: A contactless, nonvolatile metal oxide semiconductor memory device having a rectangular array of memory cells interconnected by word-lines in the row direction of the array and bit-lines in the column direction of the array. Each memory cell has a structurally asymmetrical pair of floating gate, MOS field effect transistors of the same row that share a common source region (bit line) within a semiconductor substrate. The asymmetry of the structure of the floating gates of the two transistors enables programming/reading and monitoring of the cell to be effected simultaneously. The structure of the floating gate is also responsible for a relatively large capacitive coupling between the floating gates and the control gate (word line) which lies above them. Since the floating gates essentially serve as a mask for implantation of program/read and monitor drain regions within the substrate, fabrication of the device incorporates self-aligning process steps.

Abstract: A non-volatile memory cell, comprising a semiconductor substrate having a first conductivity type. A control region is formed of said first conductivity type in the substrate and a control region oxide formed over the control region. The cell includes a program element having a first active region of a second conductivity type formed in said substrate, a doped or implanted region adjacent to said first active region, and a gate oxide overlying at least the channel region. An active region oxide covers a portion of the first active region. A floating gate is formed over said semiconductor substrate on said active region oxide and said control region oxide.

Abstract: A method for adjusting Vt while minimizing parasitic capacitance for low voltage high speed semiconductor devices. The method uses shadow effects and an angled punch through prevention implant between vertical structures to provide a graded implant. The implant angle is greater than or equal to arc tangent of S/H where S is the horizontal distance between, and H is the height of, such vertical structures.

Abstract: A nonvolatile semiconductor memory device includes an n-type region which is in contact with n+ drain diffusion region at a surface of p-type silicon substrate and covers the periphery thereof. The device also includes a p-type impurity region which is in contact with n-type region and covers the periphery thereof. The n+ drain diffusion region, n-type region and p+ impurity region extend to region located immediately under the floating gate electrode. Thereby, the nonvolatile semiconductor memory device has a structure which can promote injection of high energy electrons along a gate electrode direction.

Abstract: A non-volatile memory cell structure comprises a floating gate, a reverse breakdown injection element at least partially formed in a polysilicon layer and operatively coupled to the floating gate, and a transistor at least partially formed in a region of a semiconductor substrate, operatively coupled to the floating gate. In a further aspect, a control gate is capacitively coupled to the floating gate and is formed in said polysilicon layer. The reverse breakdown electron injection element comprises a first, second, and third active regions, the first and second regions comprising a first p/n junction, the second and third active regions comprising a second p/n junction.

Abstract: Floating gate stacks having a metal control gate and a polysilicon floating gate and their methods of fabrication that are particularly useful for floating gate memory cells and apparatus produced therefrom. The metal control gate permits reduced gate resistance and gate height over polysilicon or silicide control gates. An oxidation barrier is formed on sidewalls of the metal control gate to protect it from oxidation during oxidation of sidewalls of the polysilicon floating gate. The oxidation barrier is useful in reducing peeling, stress and related oxidation problems when using metals such as tungsten in the metal control gate.

Abstract: A semiconductor memory device is formed on a doped semiconductor substrate, and covered with a tunnel oxide layer covered in turn with a doped first polysilicon layer. The first polysilicon layer is patterned into a pair of floating gate electrodes. An interelectrode dielectric layer covers the floating gate electrodes, the sidewalls of the floating gate electrodes and the edges of the tunnel oxide below the floating gate electrodes. A second polysilicon layer overlies the interelectrode dielectric layer and is in turn covered by a tungsten silicide layer. A second dielectric layer covers the tungsten silicide layer. A control gate electrode which spans the pair of floating gate electrodes is formed by the second polysilicon layer, the tungsten silicide and the first and second dielectric layers patterned into a gate electrode stack providing a control gate electrode spanning across the pair of floating gate electrodes.

Abstract: The present invention provides a method for reducing the gate aspect ratio of a flash memory device. The method includes forming a tunnel oxide layer on a substrate; forming a polysilicon layer on the tunnel oxide layer; forming an insulating layer on the polysilicon layer; forming a control gate layer on the polysilicon layer; etching at least the tunnel oxide layer, the insulating layer, and the control gate layer to form at least two stack structures; forming a plurality of spacers at sides of the at least two stack structures; and filling at least one gap between the at least two stack structures with an oxide, where the control gate layer provides a gate aspect ratio which allows for a maximum step coverage by the oxide. In a preferred embodiment, the method uses nickel silicide instead of the conventional tungsten silicide in the control gate layers of the cells of the device.

Abstract: A two-dimensional array of single polysilicon DRAM cells is disclosed. The array comprises a plurality of DRAM cells arranged in a two-dimensional matrix, wherein each of the DRAM cells comprises: a deep n-well in a silicon substrate; a p-well within the deep n-well; a gate structure over and straddling the deep n-well and the p-well; and a n+ region within the p-well and adjacent to a sidewall of the gate structure. The array is connected together by a plurality of column bitlines, each of the column bitlines connected to the n+ regions of all of the DRAM cells that are in a common column. Further, a plurality of row wordlines are provided, each of the row wordlines connected to the gate structures of all of the DRAM cells that are in a common row.

Abstract: A novel method of forming a polysilicon gate tip (poly tip) for enhanced F-N tunneling in split-gate flash memory cells is disclosed. The poly tip is further enhanced by forming a notched nitride layer over the tip. At the same time, a method of forming a self-aligned source (SAS) line is disclosed. A relatively thin polygate is formed so as to decrease the growth of the protrusion of conventional gate bird's beak (GBB) to a smaller and sharper tip. It will be known by those skilled in the art that GBB is easily damaged during conventional poly etching where polyoxide is used as a hard mask. To use polyoxide as a hard mask, thick polysilicon is needed in the first place. Such thick poly will increase gate coupling ratio, which has the attendant effect of degrading program and erasing performance of the memory cell.

Abstract: A programmable semiconductor device and a method of manufacturing the same. The device includes: (1) a substrate composed at least in part of silicon, (2) a dielectric layer located over the substrate and (3) a control gate located over the dielectric layer wherein the dielectric layer contains a substantial concentration of an isotope of hydrogen.