Abstract: A nonvolatile memory cell comprising a switchable resistor memory element and a thin-film three-terminal switching device, preferably a MOSFET, in series. The switchable resistor memory element has the property of having at least two stable resistance states, for example a high-resistance state and a low-resistance state. It is switched between the two states, and its resistance state (and thus the data state of the cell) is sensed by providing appropriate current through the three-terminal switching device. Preferred embodiments of the present invention include a highly dense monolithic three dimensional memory array in which multiple memory levels of such memory cells are formed above a single substrate such as a monocrystalline silicon wafer.

Abstract: A nonvolatile memory cell is provided, the cell comprising a transistor in series with resistance-switching material, which can be switched between at least two stable resistance states, for example a high-resistance state and a low-resistance state. In preferred embodiments the transistor is a TFT, having a channel region not formed in a monocrystalline wafer substrate. In preferred embodiments the transistor may have either a vertically oriented channel or a laterally oriented channel. Either embodiment can be formed in a monolithic three dimensional memory array in which multiple memory levels can be formed above a single substrate, forming a highly dense nonvolatile memory array.

Abstract: There is provided a monolithic three dimensional TFT mask ROM array. The array includes a plurality of device levels. Each of the plurality of device levels contains a first set of enabled TFTs and a second set of partially or totally disabled TFTs.

Abstract: In a novel rewriteable nonvolatile memory cell formed above a substrate, a diode is paired with a reversible resistance-switching material, preferably a metal oxide or nitride such as, for example, NiO, Nb2O5, TiO2, HfO2, Al2O3, MgOx, CrO2, VO, BN, and AlN. In preferred embodiments, the diode is formed as a vertical pillar disposed between conductors. Multiple memory levels can be stacked to form a monolithic three dimensional memory array. In some embodiments, the diode comprises germanium or a germanium alloy, which can be deposited and crystallized at relatively low temperatures, allowing use of aluminum or copper in the conductors.

Abstract: In a novel nonvolatile memory cell formed above a substrate, a diode is paired with a reversible resistance-switching material, preferably a metal oxide or nitride such as, for example, NixOy, NbxOy, TixOy, HFxOy, AlxOy, MgxOy, CoxOy, CrxOy, VxOy, ZnxOy, ZrxOy, BxNy, and AlxNy. In preferred embodiments, the diode is formed as a vertical pillar disposed between conductors. Multiple memory levels can be stacked to form a monolithic three dimensional memory array. In some embodiments, the diode comprises germanium or a germanium alloy, which can be deposited and crystallized at relatively low temperatures, allowing use of aluminum or copper in the conductors. The memory cell of the present invention can be used as a rewriteable memory cell or a one-time-programmable memory cell, and can store two or more data states.

Abstract: There is provided a monolithic three dimensional array of charge storage devices which includes a plurality of device levels, wherein at least one surface between two successive device levels is planarized by chemical mechanical polishing.

Abstract: A decoding circuit for non-binary groups of memory line drivers is disclosed. In one embodiment, an integrated circuit is disclosed comprising a binary decoder and circuitry operative to perform a non-binary arithmetic operation, wherein a result of the non-binary arithmetic operation is provided as input to the binary decoder. In another embodiment, an integrated circuit is disclosed comprising a memory array comprising a plurality of array lines, a non-integral-power-of-two number of array line driver circuits, and control circuitry configured to select one of the array line driver circuits. The control circuitry can comprise a binary decoder and a pre-decoder portion that performs a non-binary arithmetic operation. The concepts described herein may be used alone or in combination.

Abstract: In formation of monolithic three dimensional memory arrays, a photomask may be used more than once. Reuse of a photomask creates second, third or more instances of reference marks used by the stepper to achieve alignment (alignment marks) and to measure alignment achieved (overlay marks) directly above prior instances of the same reference mark. The prior instances of the same reference mark may cause interference with the present instance of the reference mark, complicating alignment and measurement. Using the methods of the present invention, blocking structure is created vertically interposed between subsequent instances of the same reference mark, preventing interference.

Abstract: A multi-headed word line driver circuit incorporates bent-gate transistors to reduce the pitch otherwise achievable for interfacing to tightly-pitched array lines. In certain exemplary embodiments, a three-dimensional memory array includes multiple memory blocks and array lines traversing horizontally across at least one memory block. Vertical active area stripes are disposed beneath a first memory block, and a respective plurality of bent-gate electrodes intersects each respective active area stripe to define individual source/drain regions. Every other source/drain region is coupled to a bias node for the active area stripe, and remaining source/drain regions are respectively coupled to a respective array line associated with the first memory block, thereby forming a respective first driver transistor for the respective array line.

Abstract: In a first preferred embodiment of the present invention, conductive features are formed on a first dielectric etch stop layer, and a second dielectric material is deposited over and between the conductive features. A via etch to the conductive features which is selective between the first and second dielectrics will stop on the dielectric etch stop layer, limiting overetch. In a second embodiment, a plurality of conductive features is formed in a subtractive pattern and etch process, filled with a dielectric fill, and then a surface formed coexposing the conductive features and dielectric fill. A dielectric etch stop layer is deposited on the surface, then a third dielectric covers the dielectric etch stop layer. When a contact is etched through the third dielectric, this selective etch stops on the dielectric etch stop layer. A second etch makes contact to the conductive features.

Abstract: A substantially planar surface coexposes conductive or semiconductor features and a dielectric etch stop material. A second dielectric material, different from the dielectric etch stop material, is deposited on the substantially planar surface. A selective etch etches a hole or trench in the second dielectric material, so that the etch stops on the conductive or semiconductor feature and the dielectric etch stop material. In a preferred embodiment the substantially planar surface is formed by filling gaps between the conductive or semiconductor features with a first dielectric such as oxide, recessing the oxide, filling with a second dielectric such as nitride, then planarizing to coexpose the nitride and the conductive or semiconductor features.

Abstract: A memory cell is formed of a semiconductor junction diode interposed between conductors. The cell is programmed by rendering the memory cell very high-resistance, such that current no longer flows between the conductors on application of a read voltage. In this cell the diode behaves as a fuse. The semiconductor junction diode comprises silicon, the silicon crystallized in contact with a silicide. The silicide may provide a template for crystallization, decreasing the defect density of the silicon and improving its conductivity. It is advantageous to reduce a dielectric layer (such as an oxide, nitride, or oxynitride) intervening between the silicon and the silicon-forming metal during the step of forming the silicide.

Abstract: A three-dimensional flash memory array incorporates thin film transistors having a charge storage dielectric arranged in series-connected NAND strings to achieve a 4F2 memory cell layout. The memory array may be programmed and erased using only tunneling currents, and no leakage paths are formed through non-selected memory cells. Each NAND string includes two block select devices for respectively coupling one end of the NAND string to a global bit line, and the other end to a shared bias node. Pairs of NAND strings within a block share the same global bit line. The memory cells are preferably depletion mode SONOS devices, as are the block select devices. The memory cells may be programmed to a near depletion threshold voltage, and the block select devices are maintained in a programmed state having a near depletion mode threshold voltage. NAND strings on more than one layer may be connected to global bit lines on a single layer.

Abstract: The present invention provides for a via and staggered routing level structure. Vertically overlapping vias connect to two or more routing levels formed at different heights. The routing levels are either both formed above or both formed below the vias, and all are formed above a semiconductor substrate wafer. In this way vias can be formed having a pitch smaller than the pitch of either the first routing level or the second routing level, saving space.

Abstract: The invention provides for a vertically oriented junction diode having a contact-antifuse unit in contact with one of its electrodes. The contact-antifuse unit is formed either above or below the junction diode, and comprises a silicide with a dielectric antifuse layer formed on and in contact with it. In preferred embodiments, the silicide is cobalt silicide, and the antifuse is preferably silicon oxide, silicon nitride, or silicon oxynitride grown on the cobalt silicide. The junction diode and contact-antifuse unit can be used as a memory cell, which is advantageously used in a monolithic three dimensional memory array.

Abstract: There is provided a monolithic three dimensional TFT mask ROM array. The array includes a plurality of device levels. Each of the plurality of device levels contains a first set of enabled TFTs and a second set of partially or totally disabled TFTs.

Abstract: There is provided a monolithic three dimensional TFT mask ROM array. The array includes a plurality of device levels. Each of the plurality of device levels contains a first set of enabled TFTs and a second set of partially or totally disabled TFTs.

Abstract: A three-dimensional flash memory array incorporates thin film transistors having a charge storage dielectric arranged in series-connected NAND strings to achieve a 4F2 memory cell layout. The memory array may be programmed and erased using only tunneling currents, and no leakage paths are formed through non-selected memory cells. Each NAND string includes two block select devices for respectively coupling one end of the NAND string to a global bit line, and the other end to a shared bias node. Pairs of NAND strings within a block share the same global bit line. The memory cells are preferably depletion mode SONOS devices, as are the block select devices. The memory cells may be programmed to a near depletion threshold voltage, and the block select devices are maintained in a programmed state having a near depletion mode threshold voltage. NAND strings on more than one layer may be connected to global bit lines on a single layer.

Abstract: A three-dimensional flash memory array incorporates thin film transistors having a charge storage dielectric arranged in series-connected NAND strings to achieve a 4F2 memory cell layout. The memory array may be programmed and erased using only tunneling currents, and no leakage paths are formed through non-selected memory cells. Each NAND string includes two block select devices for respectively coupling one end of the NAND string to a global bit line, and the other end to a shared bias node. Pairs of NAND strings within a block share the same global bit line. The memory cells are preferably depletion mode SONOS devices, as are the block select devices. The memory cells may be programmed to a near depletion threshold voltage, and the block select devices are maintained in a programmed state having a near depletion mode threshold voltage. NAND strings on more than one layer may be connected to global bit lines on a single layer.

Abstract: There is provided a monolithic three dimensional TFT mask ROM array. The array includes a plurality of device levels. Each of the plurality of device levels contains a first set of enabled TFTs and a second set of partially or totally disabled TFTs.