Abstract: The invention advantageously provides a nonvolatile memory device and associated methods therefore, and, more particularly, an optimally designed nonvolatile memory device and methods therefor that advantageously prevent data loss in its trapping layer. A preferred embodiment of the method for operating a nonvolatile memory cell according to the invention advantageously comprises the steps of programming the memory cell, injecting electrons into a trapping layer of the memory cell from a semiconductor substrate, erasing the memory cell, detrapping the memory cell, and repeating the erasing and detrapping steps until a threshold voltage of the memory cell reaches a predetermined value. For the detrapping step, electrons can be detrapped from the trapping layer to a channel region of the memory cell, or to a gate of the memory cell.

Abstract: A fabrication method for a flash memory device with a split floating gate is described. The method provides a substrate, wherein an oxide layer and a patterned sacrificial layer are sequentially formed on the substrate. Ion implantation is then conducted to form source/drain regions with lightly doped source/drain regions in the substrate beside the sides of the patterned sacrificial layer using the patterned sacrificial layer as a mask. Isotropic etching is further conducted to remove a part of the patterned sacrificial layer, followed by forming two conductive spacers on the sidewalls of the patterned sacrificial layer. The patterned sacrificial layer and oxide layer that is exposed by the two conductive spacers are then removed to form two floating gates. Subsequently, a dielectric layer and a control gate are formed on the substrate.

Abstract: An erasing method for the memory cells of a non-volatile memory is provided. Each memory cell comprises a gate, a source, a drain, an electron-trapping layer and a substrate. The data within the memory cell is erased by applying a first voltage to the control gate, applying a second voltage to the source, applying a third voltage to the drain and applying a fourth voltage to the substrate. The electrons are pulled from the electron-trapping layer into the channel by negative gate F-N tunneling effect.

Abstract: A preferred embodiment of the invention provides a trapping nonvolatile memory cell comprising a P type semiconductor substrate with a N+ source and a N+ drain being formed on the semiconductor substrate, a channel being formed between the source and the drain. A first isolating layer, a nonconducting charge trapping layer, a second isolating layer and a gate are sequentially formed above the channel. The trapping layer stores an amount of electrons as the nonvolatile memory cell is erased.

Abstract: A virtual ground nonvolatile memory cell array is formed by a plurality of adjacent nonvolatile memory cells arranged in rows and columns so as to form an array. Each of the nonvolatile memory cells is formed by an N channel MOSFET with a trapping layer formed between two isolating layers. In the erase state, the trapping layer stores an amount of electrons. A method for programming the virtual ground nonvolatile memory cell array is also disclosed. The potentials applied to the bitlines and wordlines in the array are preset to program nonvolatile memory cells and not to disturb cells adjacent to the nonvolatile memory cell to be programmed.

Abstract: A NROM cell for reducing for reducing the second-bit effect is described. The NORM cell of the present invention is formed with a substrate, a silicon oxide/silicon nitride/silicon oxide (ONO) layer disposed on the substrate, a gate disposed on the silicon oxide/silicon nitride/silicon oxide layer, source/drain regions configured in the substrate beside the gate, and a shallow pocket doped region configured between the source/drain regions and the ONO layer beside the gate. The depth of the shallow pocket doped region is sufficiently small to prevent interference to the current flow that travels to the source/drain regions.

Abstract: A non-volatile memory is described, which comprises a plurality of memory cells, a plurality of word lines, a plurality of drain lines and a plurality of source lines. Two adjacent memory cells in the same row share a source and are grouped into a cell pair, and all of the cell pairs are arranged in rows and columns, wherein two cell pairs in the same row share a drain. The sources of the memory cells in the same row are connected to a source line, and the drains of the memory cells in the same row are connected to a drain line. The gates of the memory cells in the same column are coupled to a word line.

Abstract: A virtual ground nonvolatile memory cell array is formed by a plurality of adjacent nonvolatile memory cells arranged in rows and columns so as to form an array. Each of the nonvolatile memory cells is formed by an N channel MOSFET with a trapping layer formed between two isolating layers. In the erase state, the trapping layer stores an amount of electrons. A method for programming the virtual ground nonvolatile memory cell array is also disclosed. The potentials applied to the bitlines and wordlines in the array are preset to program nonvolatile memory cells and not to disturb cells adjacent to the nonvolatile memory cell to be programmed.

Abstract: A preferred embodiment of the invention provides a trapping nonvolatile memory cell comprising a P type semiconductor substrate with a N+ source and a N+ drain being formed on the semiconductor substrate, a channel being formed between the source and the drain. A first isolating layer, a nonconducting charge trapping layer, a second isolating layer and a gate are sequentially formed above the channel. The trapping layer stores an amount of electrons as the nonvolatile memory cell is erased.

Abstract: A method of a read scheme for a non-volatile memory cell. The non-volatile memory cell includes a substrate, a source, a drain and a gate above a channel separated by a nonconducting charge trapping material sandwiched between first and second insulating layers. The method applies a first positive drain-to-source bias, a second positive source-to-substrate bias, and a third positive gate-to-source bias to read the source-side charges trapped in the trapping material near the source side.

Abstract: A method of an erase scheme for a non-volatile memory cell. The non-volatile memory cell includes a substrate, source, drain with a channel region and a gate above the channel region separated by nonconducting charge-trapping material sandwiched between first and second insulating layers. The method includes the following steps. First, hot hole erase is performed to inject hot holes into the nonconducting charge-trapping material to eliminate first electrons trapped in the nonconducting charge-trapping material and causing some holes to remain in the second insulating layer. Finally, soft anneal is performed to inject second electrons to the second insulating layer to eliminate the holes left in the second insulating layer.

Abstract: A qualification test method for a non-volatile memory includes determining a relation curve between the programming voltage and the lifetime of the memory cell. A programming voltage with respect to the memory array within the expected lifetime is estimated. According to the relation curve, the accelerating test voltage and the test time period corresponding to the programming voltage operated in the expected lifetime are computed out. The test is performed for the test time period under the accelerating test voltage. All the memory cells at the programmed state are tested to see if the original programmed state still remains. If the programmed state remains, the memory array is judged to have the life period. If the programmed state does not remain, the memory array is judged to have no the life period.

Abstract: First of all, a semiconductor substrate is provided, wherein the semiconductor substrate has a dielectric layer thereon and two insulated regions that are individually located on the boundary of the semiconductor substrate. Then a first ion implanting process is performed to form an ion-implanting region in the semiconductor substrate between two insulated regions. Next, a second ion implanting process is performed to intensify the ion-implanting region in the semiconductor substrate between two insulated regions. Afterward, a third ion implanting process is performed to intensify again the ion-implanting region in the semiconductor substrate between two insulated regions. Subsequently, floating gates are formed and defined on the dielectric layer. Finally, source/drain regions are formed in the ion implanting region of the semiconductor substrate between the plurality of floating gates from each other by way of using a fourth ion implanting process.

Abstract: A fabrication method for a flash memory device with a split floating gate is described. The method provides a substrate, wherein an oxide layer and a patterned sacrificial layer are sequentially formed on the substrate Ion implantation is then conducted to form source/drain regions with lightly doped source/drain regions in the substrate beside the sides of the patterned sacrificial layer using the patterned sacrificial layer as a mask. Isotropic etching is further conducted to remove a part of the patterned sacrificial layer, followed by forming two conductive spacers on the sidewalls of the patterned sacrificial layer. The patterned sacrificial layer and oxide layer that is exposed by the two conductive spacers are then removed to form two floating gates. Subsequently, a dielectric layer and a control gate are formed on the substrate.

Abstract: A structure of a non-volatile memory including a substrate with a vertical ladder channel profile (VLCP), a stacked gate structure on the substrate, and a source/drain region in the substrate beside the stacked gate structure. The vertical ladder channel profile is a profile of the dopant concentration in a first doped region directly underneath the surface of the substrate and in a second doped directly underlying the first doped region, wherein the dopant concentration in the second doped region is larger than that in the first doped region.

Abstract: A reliability test method for a non-volatile memory. A relation curve of gate voltage versus read current degradation rate is obtained. The read current degradation rate of an actual gate voltage is estimated. From the relation curve, an accelerated test gate voltage and a test time corresponding to the actual gate voltage are obtained. With the accelerated test gate voltage, the test is continuously performed within the test time. Afterward, a test result of the memory is then obtained and, by the result, it is judged whether the data is valid or not. If the data is right (retained), the memory can be guarantied to have an expected lifetime; if the data is wrong (lost), the memory is judged as fails to pass the lifetime test.

Abstract: A method of fabricating a flash memory is disclosed. The method begins a stacked gate on the substrate. A shallow junction doping is performed on a substrate having a stacked gate already formed thereon, with the stacked gate serving as a mask, so as to form a shallow junction doped region in the substrate adjacent to both sides of the stacked gate. A mask layer is formed on the substrate to cover a top surface and sidewalls of the stacked gate, while exposing portions of the shallow junction doped region. With the mask layer serving as a mask, a deep junction doping is performed on the substrate to form a deep junction doped region in the substrate adjacent to both sides of the mask layer. After the mask layer is removed, a thermal process is performed to form a source/drain region having both the shallow junction doped region and deep junction doped region.

Abstract: A method of fabricating a flash memory is disclosed. The method begins a stacked gate on the substrate. A shallow junction doping is performed on a substrate having a stacked gate already formed thereon, with the stacked gate serving as a mask, so as to form a shallow junction doped region in the substrate adjacent to both sides of the stacked gate. A mask layer is formed on the substrate to cover a top surface and sidewalls of the stacked gate, while exposing portions of the shallow junction doped region. With the mask layer serving as a mask, a deep junction doping is performed on the substrate to form a deep junction doped region in the substrate adjacent to both sides of the mask layer. After the mask layer is removed, a thermal process is performed to form a source/drain region having both the shallow junction doped region and deep junction doped region.

Abstract: An accelerated test for a non-volatile memory. A threshold voltage variation standard for assessment is selected. A set of negative gate bias voltages is applied to the gate terminals of the non-volatile memory to conduct the accelerated testing and obtain a test result. A curve relating lifetime and negative gate bias voltage is derived from the test result. According to the threshold voltage variation standard, the lifetime of the non-volatile memory is found. A word line negative gate bias voltage generator is coupled to a word line driver to apply a set of negative gate bias voltages to the gate terminals of programmed memory cells and conduct an accelerated testing.