| Patent application number | Description | Published |
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| 20080248621 | Integrated Non-Volatile Memory And Peripheral Circuitry Fabrication - Non-volatile memory and integrated memory and peripheral circuitry fabrication processes are provided. Sets of charge storage regions, such as NAND strings including multiple non-volatile storage elements, are formed over a semiconductor substrate using a layer of charge storage material such as a first layer of polysilicon. An intermediate dielectric layer is provided over the charge storage regions. A layer of conductive material such as a second layer of polysilicon is deposited over the substrate and etched to form the control gates for the charge storage regions and the gate regions of the select transistors for the sets of storage elements. The first layer of polysilicon is removed from a portion of the substrate, facilitating fabrication of the select transistor gate regions from only the second layer of polysilicon. Peripheral circuitry formation is also incorporated into the fabrication process to form the gate regions for devices such as high voltage and logic transistors. The gate regions of these devices can be formed from the layer forming the control gates of the memory array. | 10-09-2008 |
| 20080248622 | Methods Of Fabricating Non-Volatile Memory With Integrated Peripheral Circuitry And Pre-Isolation Memory Cell Formation - Non-volatile semiconductor memory devices with dual control gate memory cells and methods of forming the same using integrated peripheral circuitry formation are provided. Strips of charge storage material elongated in a row direction across the surface of a substrate with strips of tunnel dielectric material therebetween are formed. Forming the strips defines the dimension of the resulting charge storage structures in the column direction. The strips of charge storage material can include multiple layers of charge storage material to form composite charge storage structures in one embodiment. Strips of control gate material are formed between strips of charge storage material adjacent in the column direction. The strips of charge storage and control gate material are divided along their lengths in the row direction as part of forming isolation trenches and columns of active areas. After dividing the strips, the charge storage material at the peripheral circuitry region of the substrate is etched to define a gate dimension in the column direction for a peripheral transistor. Control gate interconnects can be formed to connect together rows of isolated control gates to extrinsically form word lines. | 10-09-2008 |
| 20080268596 | Methods Of Fabricating Non-Volatile Memory With Integrated Select And Peripheral Circuitry And Post-Isolation Memory Cell Formation - Non-volatile semiconductor memory devices with dual control gate memory cells and methods of forming the same using integrated select and peripheral circuitry formation are provided. Strips of charge storage material elongated in a column direction across the surface of a substrate with strips of tunnel dielectric material therebetween are formed. The strips of charge storage material can include multiple layers of charge storage material to form composite charge storage structures in one embodiment. After forming isolation trenches in the substrate between active areas below the strips of charge storage material, spacer-assisted patterning is used to form a pattern at the memory array region. Strips of photoresist are patterned over a portion of the pattern at the memory array. Photoresist is also applied at the peripheral circuitry region. At least a portion of the layer stack is etched using the photoresist as a mask before removing the photoresist and etching the strips of charge storage material to form the charge storage structures. | 10-30-2008 |
| 20080316811 | METHOD FOR OPERATING NON-VOLATILE STORAGE WITH INDIVIDUALLY CONTROLLABLE SHIELD PLATES BETWEEN STORAGE ELEMENTS - A method for controlling non-volatile storage having individually controllable shield plates between storage elements. The shield plates are formed by depositing a conductive material such as doped polysilicon between storage elements and their associated word lines, and providing contacts for the shield plates. The shield plates reduce electromagnetic coupling between floating gates of the storage elements, and can be used to optimize programming, read and erase operations. In one approach, the shield plates provide a field induced conductivity between storage elements in a NAND string during a sense operation so that source/drain implants are not needed in the substrate. In some control schemes, alternating high and low voltages are applied to the shield plates. In other control schemes, a common voltage is applied to the shield plates. | 12-25-2008 |
| 20080316827 | NON-VOLATILE STORAGE WITH INDIVIDUALLY CONTROLLABLE SHIELD PLATES BETWEEN STORAGE ELEMENTS - A non-volatile storage having individually controllable shield plates between storage elements. The shield plates are formed by depositing a conductive material such as doped polysilicon between storage elements and their associated word lines, and providing contacts for the shield plates. The shield plates reduce electromagnetic coupling between floating gates of the storage elements, and can be used to optimize programming, read and erase operations. In one approach, the shield plates provide a field induced conductivity between storage elements in a NAND string during a sense operation so that source/drain implants are not needed in the substrate. In some control schemes, alternating high and low voltages are applied to the shield plates. In other control schemes, a common voltage is applied to the shield plates. | 12-25-2008 |
| 20080318379 | METHOD FOR FABRICATING NON-VOLATILE STORAGE WITH INDIVIDUALLY CONTROLLABLE SHIELD PLATES BETWEEN STORAGE ELEMENTS - A method for fabricating non-volatile storage having individually controllable shield plates between storage elements. The shield plates are formed by depositing a conductive material such as doped polysilicon between storage elements and their associated word lines, and providing contacts for the shield plates. The shield plates reduce electromagnetic coupling between floating gates of the storage elements, and can be used to optimize programming, read and erase operations. In one approach, the shield plates provide a field induced conductivity between storage elements in a NAND string during a sense operation so that source/drain implants are not needed in the substrate. In some control schemes, alternating high and low voltages are applied to the shield plates. In other control schemes, a common voltage is applied to the shield plates. | 12-25-2008 |
| 20090166704 | NON-VOLATILE STORAGE WITH SUBSTRATE CUT-OUT AND PROCESS OF FABRICATING - Shallow trench isolation regions are positioned between NAND strings (or other types of non-volatile storage). These isolation regions include sections that form concave cut-out shapes in the substrate for the NAND string (or other types of non-volatile storage). The floating gates (or other charge storage devices) of the NAND strings hang over the sections of the isolation region that form the concave cut-out shape in the substrate. To manufacture such a structure, a two step etching process is used to form the isolation regions. In the first step, isotropic etching is used to remove substrate material in multiple directions, including removing substrate material underneath the floating gates. In the second step, anisotropic etching is used to create the lower part of the isolation region. | 07-02-2009 |
| 20090251967 | NON-VOLATILE STORAGE HAVING A CONNECTED SOURCE AND WELL - A non-volatile storage device is disclosed that includes a set of connected non-volatile storage elements formed on a well, a bit line contact positioned in the well, a source line contact positioned in the well, a bit line that is connected to the bit line contact, and a source line that is connected to the source line contact and the well. | 10-08-2009 |
| 20100047979 | METHOD OF REDUCING COUPLING BETWEEN FLOATING GATES IN NONVOLATILE MEMORY - A nonvolatile memory array includes floating gates that have an inverted-T shape in cross section along a plane that is perpendicular to the direction along which floating cells are connected together to form a string. Adjacent strings are isolated by shallow trench isolation structures. | 02-25-2010 |
| 20100074014 | DATA STATE-BASED TEMPERATURE COMPENSATION DURING SENSING IN NON-VOLATILE MEMORY - Temperature effects in a non-volatile storage device are addressed by providing a data state-dependent, and optionally temperature dependent, sense current during verify and read operations. A different sense current is provided for each data state, so that a common temperature coefficient is realized for storage elements with different data states. The temperature coefficient for higher states can be reduced to that of lower states. During sensing, a sense time can be adjusted to achieve a desired sense current when a selected storage element is in a conductive state. A fixed voltage trip point may be maintained. During the sense time, a pre-charged capacitor discharges into a selected storage element such as via a bit line and NAND string, when the selected storage element is in a conductive state. The discharge level is translated to a current which is compared to a state-dependent, and optionally temperature dependent, reference current. | 03-25-2010 |
| 20100074016 | DATA RETENTION OF LAST WORD LINE OF NON-VOLATILE MEMORY ARRAYS - Techniques are disclosed herein for operating non-volatile storage. The techniques compensate for differences in floating gate coupling effect experienced by non-volatile storage elements on different word lines. An erase of a group of non-volatile storage elements is performed. A set of the non-volatile storage elements are for storing data and at least one of the non-volatile storage elements is a dummy that is not for storing data. The dummy is a neighbor to one of the data non-volatile storage elements. The data non-volatile storage elements are programmed at some point after the erase. Then, a programming voltage is applied to the dummy non-volatile storage element to increase the threshold voltage of the dummy to cause floating gate coupling effect to the neighbor non-volatile storage element to compensate for lesser floating gate coupling effect that the neighbor experienced during programming. | 03-25-2010 |
| 20100091569 | METHODS OF FORMING FLASH DEVICE WITH SHARED WORD LINES - Word lines of a NAND flash memory array are formed by concentric, rectangular shaped, closed loops that have a width of approximately half the minimum feature size of the patterning process used. The resulting circuits have word lines linked together so that peripheral circuits are shared. Separate erase blocks are established by shield plates. | 04-15-2010 |
| 20100172187 | ROBUST SENSING CIRCUIT AND METHOD - A sense amplifier is disclosed. One embodiment is a sensing circuit that includes a sensing device and a sense transistor coupled to the sensing device. A first switch that is coupled to the sense transistor and to the sensing device causes the sensing device to be charged to a first voltage that is a function of the threshold voltage of the sense transistor. One or more second switches that are coupled to the sensing device and to a target element. The second switches couple the sensing device to the target element to modify the first voltage on the sensing device and decouple the target element from the sensing device during a sense phase in which the modified first voltage is applied to the sense transistor. A condition of the target element is determined based on whether or not the sense transistor turns on in response to applying the modified first voltage to the sense transistor. | 07-08-2010 |
| 20100238729 | NON-VOLATILE MEMORY WITH REDUCED LEAKAGE CURRENT FOR UNSELECTED BLOCKS AND METHOD FOR OPERATING SAME - A memory device with reduced leakage current during programming and sense operations, and a method for operating such a memory device. In a non-volatile memory device, current leakage at the drain select gates of NAND strings can occur in unselected blocks when a selected block undergoes a program or read operation, and the bit lines are shared by the blocks. In one approach, in which a common transfer gate driver is provided for both blocks, the drain select gates are pre-charged at an optimum level, which minimizes leakage, and subsequently floated while a program or read voltage is applied to a selected word line in the selected block. In another approach, a separate transfer gate driver is provided for the unselected block so that the optimal select gate voltage can be driven in the unselected block, even while the program or read voltage is applied in the selected block. | 09-23-2010 |
| 20100240182 | Spacer Patterns Using Assist Layer For High Density Semiconductor Devices - High density semiconductor devices and methods of fabricating the same are provided. Spacer fabrication techniques are utilized to form circuit elements having reduced feature sizes, which in some instances are smaller than the smallest lithographically resolvable element size of the process being used. Spacers are formed that serve as a mask for etching one or more layers beneath the spacers. An etch stop pad layer having a material composition substantially similar to the spacer material is provided between a dielectric layer and an insulating sacrificial layer such as silicon nitride. When etching the sacrificial layer, the matched pad layer provides an etch stop to avoid damaging and reducing the size of the dielectric layer. The matched material compositions further provide improved adhesion for the spacers, thereby improving the rigidity and integrity of the spacers. | 09-23-2010 |
| 20100270608 | Integrated Circuits And Fabrication Using Sidewall Nitridation Processes - Semiconductor devices are provided with encapsulating films for protection of sidewall features during fabrication processes, such as etching to form isolation regions. In a non-volatile flash memory, for example, a trench isolation process is divided into segments to incorporate an encapsulating film along the sidewalls of charge storage material. A pattern is formed over the layer stack followed by etching the charge storage material to form strips elongated in the column direction across the substrate, with a layer of tunnel dielectric material therebetween. Before etching the substrate, an encapsulating film is formed along the sidewalls of the strips of charge storage material. The encapsulating film can protect the sidewalls of the charge storage material during subsequent cleaning, oxidation and etch processes. In another example, the encapsulating film is simultaneously formed while etching to form strips of charge storage material and the isolation trenches. | 10-28-2010 |
| 20100273299 | METHOD FOR FABRICATING NON-VOLATILE STORAGE WITH INDIVIDUALLY CONTROLLABLE SHIELD PLATES BETWEEN STORAGE ELEMENTS - A method for fabricating non-volatile storage having individually controllable shield plates between storage elements. The shield plates are formed by depositing a conductive material such as doped polysilicon between storage elements and their associated word lines, and providing contacts for the shield plates. The shield plates reduce electromagnetic coupling between floating gates of the storage elements, and can be used to optimize programming, read and erase operations. In one approach, the shield plates provide a field induced conductivity between storage elements in a NAND string during a sense operation so that source/drain implants are not needed in the substrate. In some control schemes, alternating high and low voltages are applied to the shield plates. In other control schemes, a common voltage is applied to the shield plates. | 10-28-2010 |
| 20100330806 | Method of forming contact hole arrays using a hybrid spacer technique - One embodiment of the invention provides a method of forming a plurality of contact holes, including forming a first feature and a second feature over an underlying material, forming sidewall spacers on the first and second features, removing the first and second features without removing the sidewall spacers, forming a cover mask at least partially exposing the sidewall spacers, and etching the underlying material using the cover mask and the sidewall spacers as a mask to form the plurality of contact holes. | 12-30-2010 |
| 20110020992 | Integrated Nanostructure-Based Non-Volatile Memory Fabrication - Nanostructure-based charge storage regions are included in non-volatile memory devices and integrated with the fabrication of select gates and peripheral circuitry. One or more nanostructure coatings are applied over a substrate at a memory array area and a peripheral circuitry area. Various processes for removing the nanostructure coating from undesired areas of the substrate, such as target areas for select gates and peripheral transistors, are provided. One or more nanostructure coatings are formed using self-assembly based processes to selectively form nanostructures over active areas of the substrate in one example. Self-assembly permits the formation of discrete lines of nanostructures that are electrically isolated from one another without requiring patterning or etching of the nanostructure coating. | 01-27-2011 |
| 20110026327 | BIT-LINE CONNECTIONS FOR NON-VOLATILE STORAGE - Bit line connections for non-volatile storage devices and methods for fabricating the same are disclosed. At least two different types of bit line connections may be used between memory cells and bit lines. The different types of bit line connections may be structurally different from each other as follows. One type of bit line connection may include a metal pad between an upper via and lower via. Another type of bit line connection may include an upper via and lower via, but does not include the metal pad. Three rows of bit line connections may be used to relax the pitch. For example, two rows of bit line connections on the outside may have the metal pad, whereas bit line connections in the middle row do not have the metal pad. | 02-03-2011 |
| 20110111583 | METHOD OF REDUCING COUPLING BETWEEN FLOATING GATES IN NONVOLATILE MEMORY - A nonvolatile memory array includes floating gates that have an inverted-T shape in cross section along a plane that is perpendicular to the direction along which floating cells are connected together to form a string. Adjacent strings are isolated by shallow trench isolation structures. | 05-12-2011 |
| 20110159649 | NON-VOLATILE STORAGE WITH SUBSTRATE CUT-OUT AND PROCESS OF FABRICATING - Shallow trench isolation regions are positioned between NAND strings (or other types of non-volatile storage). These isolation regions include sections that form concave cut-out shapes in the substrate for the NAND string (or other types of non-volatile storage). The floating gates (or other charge storage devices) of the NAND strings hang over the sections of the isolation region that form the concave cut-out shape in the substrate. To manufacture such a structure, a two step etching process is used to form the isolation regions. In the first step, isotropic etching is used to remove substrate material in multiple directions, including removing substrate material underneath the floating gates. In the second step, anisotropic etching is used to create the lower part of the isolation region. | 06-30-2011 |
