Abstract: Provided is a nonvolatile storage device (200) capable of stably operating without increasing a size of a selection transistor included in each of memory cells. The nonvolatile storage device (200) includes: a semiconductor substrate (301) which has a P-type well (301a) of a first conductivity type; a memory cell array (202) which includes memory cells (M11) or the like each of which includes a variable resistance element (R11) and a transistor (N11) that are formed above the semiconductor substrate (301) and connected in series; and a substrate bias circuit (220) which applies, to the P-type well (301a), a bias voltage in a forward direction with respect to a source and a drain of the transistor (N11), when a voltage pulse for writing is applied to the variable resistance element (R11) included in the selected memory cell (M11) or the like.

Abstract: A memory element (3) arranged in matrix in a memory device and including a resistance variable element (1) which switches its electrical resistance value in response to a positive or negative electrical pulse applied thereto and retains the switched electrical resistance value; and a current control element (2) for controlling a current flowing when the electrical pulse is applied to the resistance variable element (1); wherein the current control element (2) includes a first electrode; a second electrode; and a current control layer sandwiched between the first electrode and the second electrode; and wherein the current control layer comprises SiNx, and at least one of the first electrode and the second electrode comprises ?-tungsten.

Abstract: In a current rectifying element (10), a barrier height ?A of a center region (14) of a barrier layer (11) in a thickness direction thereof sandwiched between a first electrode layer (12) and a second electrode layer (13) is formed to be larger than a barrier height ?B of a region in the vicinity of an interface (17) between the barrier layer (11) and the first electrode layer (12) and an interface (17) between the barrier layer (11) and the second electrode layer (13). The barrier layer (11) has, for example, a triple-layer structure of barrier layers (11a), (11b) and (11c). The barrier layers (11a), (11b) and (11c) are, for example, formed by SiN layers of SiNx2, SiNx1, and SiNx1 (X1<X2). Therefore, the barrier layer (11) has a barrier height in which the shape changes in a stepwise manner and the height of the center region 14 is large.

Abstract: A non-volatile semiconductor memory device which simultaneously possesses a non-volatile memory cell region which possesses an isolating insulation film which has been formed selectively within a semiconductor substrate, which also possesses a first electroconductive film (floating gate electrode) via a first gate insulating film which has been formed on the semiconductor substrate surface, and which also possesses a metal film (control gate electrode) via a second gate insulating film which has been formed above said electroconductive film and a peripheral transistor region which possesses a metal film (gate electrode) via a third gate insulating film which has been formed above the semiconductor substrate surface.

Abstract: A proposed non-volatile semiconductor memory and a method of manufacturing the same are directed to performing stable and highly reliable operations. First, grooves are formed in a p-type silicon semiconductor substrate, and impurity diffusion layers are formed on the bottom surfaces of the grooves. A gate insulating film is then formed on the p-type silicon semiconductor substrate. This gate insulating film has a three-layer structure in which a first insulating film made of a silicon oxide film, a charge capturing film made of a silicon nitride film, and a second insulating film made of a silicon oxide film, are laminated in this order. A gate electrode is then formed on the gate insulating film. A convexity formed by the grooves serves as the channel region of the non-volatile semiconductor memory. Even if the device size is reduced, an effective channel length can be secured in this non-volatile semiconductor memory. Thus, excellent stability and reliability can be achieved.

Abstract: A proposed non-volatile semiconductor memory and a method of manufacturing the same are directed to performing stable and highly reliable operations. First, grooves are formed in a p-type silicon semiconductor substrate, and impurity diffusion layers are formed on the bottom surfaces of the grooves. A gate insulating film is then formed on the p-type silicon semiconductor substrate. This gate insulating film has a three-layer structure in which a first insulating film made of a silicon oxide film, a charge capturing film made of a silicon nitride film, and a second insulating film made of a silicon oxide film, are laminated in this order. A gate electrode is then formed on the gate insulating film. A convexity formed by the grooves serves as the channel region of the non-volatile semiconductor memory. Even if the device size is reduced, an effective channel length can be secured in this non-volatile semiconductor memory. Thus, excellent stability and reliability can be achieved.

Abstract: A proposed non-volatile semiconductor memory and a method of manufacturing the same are directed to performing stable and highly reliable operations. First, grooves are formed in a p-type silicon semiconductor substrate, and impurity diffusion layers are formed on the bottom surfaces of the grooves. A gate insulating film is then formed on the p-type silicon semiconductor substrate. This gate insulating film has a three-layer structure in which a first insulating film made of a silicon oxide film, a charge capturing film made of a silicon nitride film, and a second insulating film made of a silicon oxide film, are laminated in this order. A gate electrode is then formed on the gate insulating film. A convexity formed by the grooves serves as the channel region of the non-volatile semiconductor memory. Even if the device size is reduced, an effective channel length can be secured in this non-volatile semiconductor memory. Thus, excellent stability and reliability can be achieved.

Abstract: A nonvolatile semiconductor memory device includes a virtual-ground memory array which includes a plurality of word lines and a plurality of bit lines, a row decoder which selectively activates one of the word lines, a column decoder which applies a sense potential to one of the bit lines, and couples all the remaining ones of the bit lines to a ground potential, and a sense amplifier which compares an electric current running through the one of the bit lines with a first reference current and a second reference current so as to sense a data state of two memory cells that are connected to the one of the word lines and share the one of the bit lines, the sensed data state including a first state in which both of the two memory cells are “0”, a second state in which both of the two memory cells are “1”, and a third state in which one of the two memory cells is “1” and another of the two memory cells is “0”.

Abstract: The present invention is a method for manufacturing a non-volatile semiconductor memory cell of a structure provided with a trap gate between a word line serving as a control gate, and a channel region of a substrate, the trap gate is constructed of an insulating layer and capable of trapping a carrier. The trap gate constructed of the insulating layer can change a threshold of a transistor locally because the carriers injected and trapped inside do not move in the gate. As associated with it, the trap gate does not need to be separated between adjacent memory cells. In addition, the insulating layers for electrical isolation need to be formed on and under the trap gate constructed of the insulating layer. However, the gate insulating layer of the three-layers structure can be formed very thin and highly reliably compared with the conventional floating gate structure.

Abstract: A nonvolatile semiconductor memory comprises a pair of diffused layers formed in the surface area of a p-type silicon substrate, and a gate electrode (polysilicon film and tungsten silicide film formed on a gate oxide between the diffused layers over the p-type silicon substrate. Silicon nitride film is formed at both ends of the gate oxide so that the carrier trap characteristic may become high locally in areas near the pair of diffused layer. This configuration prevents carrier injection to other than the ends of the gate oxide, ensures reliable recording and storage, and increases reliability by preventing write and erase error.

Abstract: A non-volatile semiconductor memory device which simultaneously possesses a non-volatile memory cell region which possesses an isolating insulation film which has been formed selectively within a semiconductor substrate, which also possesses a first electroconductive film (floating gate electrode) via a first gate insulating film which has been formed on the semiconductor substrate surface, and which also possesses a metal film (control gate electrode) via a second gate insulating film which has been formed above said electroconductive film and a peripheral transistor region which possesses a metal film (gate electrode) via a third gate insulating film which has been formed above the semiconductor substrate surface.

Abstract: A nonvolatile semiconductor memory device includes a virtual-ground memory array which includes a plurality of word lines and a plurality of bit lines, a row decoder which selectively activates one of the word lines, a column decoder which applies a sense potential to one of the bit lines, and couples all the remaining ones of the bit lines to a ground potential, and a sense amplifier which compares an electric current running through the one of the bit lines with a first reference current and a second reference current so as to sense a data state of two memory cells that are connected to the one of the word lines and share the one of the bit lines, the sensed data state including a first state in which both of the two memory cells are “0”, a second state in which both of the two memory cells are “1”, and a third state in which one of the two memory cells is “1” and another of the two memory cells is “0”.

Abstract: Memory cell currents flowing through memory cells in reading data are compared with reference currents that are set in accordance with the wiring widths of word lines connected to these memory cells. The logic levels of data retained in the memory cells are detected depending on whether larger or smaller the memory cell currents are than the reference currents. Setting a plurality of reference currents for every wiring-width of word lines allows the reference currents to be set at optimum values for each memory cell having different gate widths. Since the reference currents are set according to the characteristic of memory cells, read margins improve for enhanced reliability in read operations.

Abstract: A proposed non-volatile semiconductor memory and a method of manufacturing the same are directed to performing stable and highly reliable operations. First, grooves are formed in a p-type silicon semiconductor substrate, and impurity diffusion layers are formed on the bottom surfaces of the grooves. A gate insulating film is then formed on the p-type silicon semiconductor substrate. This gate insulating film has a three-layer structure in which a first insulating film made of a silicon oxide film, a charge capturing film made of a silicon nitride film, and a second insulating film made of a silicon oxide film, are laminated in this order. A gate electrode is then formed on the gate insulating film. A convexity formed by the grooves serves as the channel region of the non-volatile semiconductor memory. Even if the device size is reduced, an effective channel length can be secured in this non-volatile semiconductor memory. Thus, excellent stability and reliability can be achieved.

Abstract: The present invention is a method for manufacturing a non-volatile semiconductor memory cell of a structure provided with a trap gate between a word line serving as a control gate, and a channel region of a substrate, the trap gate is constructed of an insulating layer and capable of trapping a carrier. The trap gate constructed of the insulating layer can change a threshold of a transistor locally because the carriers injected and trapped inside do not move in the gate. As associated with it, the trap gate does not need to be separated between adjacent memory cells. In addition, the insulating layers for electrical isolation need to be formed on and under the trap gate constructed of the insulating layer. However, the gate insulating layer of the three-layers structure can be formed very thin and highly reliably compared with the conventional floating gate structure.

Abstract: A manufacturing method includes the steps of forming a striped pattern extending in the word line direction; depositing an insulating film on the striped pattern and then forming a side wall insulating film on both side walls of the striped pattern by etching the surface throughout; selectively removing the striped pattern and then depositing a gate insulating film including a trap gate insulating film on an exposed substrate; and depositing a conductive layer throughout on the surface and removing the upper part of the conductive layer except for a region between the side wall insulating films. Consequently, the conductive layer between the side wall insulating films becomes the word line.

Abstract: Memory cell currents flowing through memory cells in reading data are compared with reference currents that are set in accordance with the wiring widths of word lines connected to these memory cells. The logic levels of data retained in the memory cells are detected depending on whether larger or smaller the memory cell currents are than the reference currents. Setting a plurality of reference currents for every wiring width of word lines allows the reference currents to be set at optimum values for each memory cell having different gate widths. Since the reference currents are set according to the characteristic of memory cells, read margins improve for enhanced reliability in read operations.

Abstract: A nonvolatile semiconductor memory comprises a pair of diffused layers formed in the surface area of a p-type silicon substrate, and a gate electrode (polysilicon film and tungsten silicide film formed on a gate oxide between the diffused layers over the p-type silicon substrate. Silicon nitride film is formed at both ends of the gate oxide so that the carrier trap characteristic may become high locally in areas near the pair of diffused layer. This configuration prevents carrier injection to other than the ends of the gate oxide, ensures reliable recording and storage, and increases reliability by preventing write and erase error.

Abstract: A non-volatile semiconductor memory device which simultaneously possesses a non-volatile memory cell region which possesses an isolating insulation film which has been formed selectively within a semiconductor substrate, which also possesses a first electroconductive film (floating gate electrode) via a first gate insulating film which has been formed on the semiconductor substrate surface, and which also possesses a metal film (control gate electrode) via a second gate insulating film which has been formed above said electroconductive film and a peripheral transistor region which possesses a metal film (gate electrode) via a third gate insulating film which has been formed above the semiconductor substrate surface.

Abstract: A control method for a nonvolatile semiconductor memory having a number of nonvolatile semiconductor memory cells formed on a surface of a semiconductor substrate each having a gate insulating film including a carrier trap layer, a gate electrode formed on the gate insulating film, and first and second diffusion regions symmetrically formed in the semiconductor substrate on both sides of the gate electrode.