Abstract: In a passive element memory array, such as a rail stack array having a continuous semiconductor region along one or both of the array lines, programming a memory cell may disturb nearby memory cells as result of a leakage path along the array line from the selected cell to the adjacent cell. This effect may be reduced substantially by changing the relative timing of the programming pulses applied to the array lines for the selected memory cell, even if the voltages are unchanged. In an exemplary three-dimensional antifuse memory array, a positive-going programming pulse applied to the anode region of the memory cell preferably is timed to lie within the time that a more lightly-doped cathode region is pulsed low.

Abstract: A thin film transistor with a channel less than 100 angstroms thick, preferably less than 80 angstroms thick, preferably less than 60 angstroms thick. The very thin channel reduces variability of threshold voltage from one TFT to the next. This is particularly advantageous for TFT memory arrays. It is possible that an extremely thin channel restricts the size of grains, forcing many small grains to be formed.

Abstract: A method for forming a contact in a three dimensional monolithic memory is disclosed. In a preferred embodiment, the method comprises depositing a conductive layer over and in contact with a plurality of antifuses, wherein said antifuses are part of a story of active devices formed above a substrate; patterning and etching said conductive layer and insulating dielectric to form a contact void; and filling the contact void, wherein the conductive layer does not comprise silicon.

Abstract: A low-density, high-resistivity layer of a PVD sputter-deposited material, preferably titanium nitride, when coupled with a dielectric, makes a superior low-leakage insulating barrier for use in semiconductor devices. The material is created by sputtering methods that cause the ions to strike the deposition surface with reduced energy, for example in an ion metal plasma chamber with no self-bias accelerating ions normal to the deposition surface, or in a standard PVD chamber with pressure increased.

Abstract: A nonvolatile memory cell is described, the memory cell comprising a semiconductor diode. The semiconductor material making up the diode is formed with significant defect density, and allows very low current flow at a typical read voltage. Application of a programming voltage permanently changes the nature of the semiconductor material, resulting in an improved diode. The programmed diode allows much higher current flow, in some embodiments one, two or three orders of magnitude higher, at the same read voltage. The difference in current allows a programmed memory cell to be distinguished from an unprogrammed memory cell. Fabrication techniques to generate an advantageous unprogrammed defect density are described. The memory cell of the present invention can be formed in a monolithic three dimensional memory array, having multiple stacked memory levels formed above a single substrate.

Abstract: The preferred embodiments described herein relate to an integrated circuit and method for selecting a set of memory-cell-layer-dependent or temperature-dependent operating conditions. In one preferred embodiment, a memory array is provided comprising a plurality of memory cells arranged in L layers stacked vertically above one another in a single integrated circuit. A memory cell layer in the memory array is selected, and one of N sets of memory-cell-layer-dependent writing conditions and/or one of K sets of memory-cell-layer-dependent reading conditions is selected based on the selected memory cell layer. In another preferred embodiment, a temperature of an integrated circuit is measured, and a set of writing conditions and/or a set of reading conditions is selected based on the measured temperature. Other preferred embodiments are provided, and each of the preferred embodiments can be used alone or in combination with one another.

Abstract: Aspects of the present invention provide for a novel photomask for patterning features for an integrated circuit, the photomask including a first area transmitting light in a first phase surrounded by second area, the second area transmitting light in a second phase, the second phase opposite the first phase. No blocking material separates the first area from the second area. After development of photoresist, the transition between the first and second area causes formation of a residual photoresist feature on the photoresist surface due to phase canceling of light. If the first area is small enough, it is nonprinting, ie., the opposite sides of the residual photoresist feature formed at its perimeter merge, forming a contiguous photoresist feature, and thus a corresponding patterned feature after etch.

Abstract: A method of forming an active device is provided. The method includes performing a first patterning operation on a first plurality of layers. This first patterning operation defines a first feature of the active device. Then, a second patterning operation can be performed on at least one layer of the first plurality of layers. This second patterning operation defines a second feature of the active device. Of importance, the first and second patterning operations are performed substantially back-to-back, thereby ensuring that the active device can accurately function.

Abstract: A three dimensional monolithic memory comprising a memory cell allowing for increased density is disclosed. In the memory cell of the present invention, a bottom conductor preferably comprising tungsten is formed. Above the bottom conductor a semiconductor element preferably comprises two diode portions and an antifuse. Above the semiconductor element are additional conductors and semiconductor elements in multiple stones of memories. The arrangement of processing steps and the choice of materials decreases aspect ratio of each memory cell, improving the reliability of gap fill and preventing etch undercut.

Abstract: The present invention relates to use of selective oxidation to oxidize silicon in the presence of tungsten and/or tungsten nitride in memory cells and memory arrays. This technique is especially useful in monolithic three dimensional memory arrays. In one aspect of the invention, the silicon of a diode-antifuse memory cell is selectively oxidized to repair etch damage and reduce leakage, while exposed tungsten of adjacent conductors and tungsten nitride of a barrier layer are not oxidized. In some embodiments, selective oxidation may be useful for gap fill. In another aspect of the invention, TFT arrays made up of charge storage memory cells comprising a polysilicon/tungsten nitride/tungsten gate can be subjected to selective oxidation to passivate the gate polysilicon and reduce leakage.

Abstract: Two types of topologically different three-dimensional integrated circuits (for example a 4-layer three-dimensional memory array and an 8-layer three-dimensional memory array) are fabricated from a single set of photo-lithographic masks. In one example, masks 1-5 are used along with other masks to create the first four levels of memory cells in both a 4-layer memory array and an 8-layer memory array. The 8-layer memory array is completed with masks used to form the top four layers of the array. An integrated circuit identification circuit generates an appropriate circuit identification signal for both types of integrated circuits by sensing whether a conductive path across some or all of the device levels of the integrated circuit is continuous, and then by selecting the appropriate circuit identification signal.

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 preferably silicon oxide, silicon nitride, or silicon oxynitride grown on the colbalt 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: A semiconductor device comprises two transistors where a gate electrode of one transistor and source or drain of another transistor are located in the same rail. A monolithic three dimensional array contains a plurality of such devices. The transistors in different levels of the array preferably have a different orientation.

Abstract: A memory array includes a sensing circuit for sensing bit line current while keeping the voltage of the selected bit line substantially unchanged. The word lines and bit lines are biased so that essentially no bias voltage is impressed across half-selected memory cells, which substantially eliminates leakage current through half-selected memory cells. The bit line current which is sensed arises largely from only the current through the selected memory cell. A noise detection line in the memory array reduces the effect of coupling from unselected word lines to the selected bit line. In a preferred embodiment, a three-dimensional memory array having a plurality of rail-stacks forming bit lines on more than one layer, includes at least one noise detection line associated with each layer of bit lines. A sensing circuit is connected to a selected bit line and to its associated noise detection line.

Abstract: The preferred embodiments described herein provide a memory device and method for storing bits in non-adjacent storage locations in a memory array. In one preferred embodiment, a memory device is provided comprising a register and a memory array. A plurality of bits provided to the memory device are stored in the register in a first direction, read from the register in a second direction, and then stored in the memory array. Bits that are adjacent to one another when provided to the memory device are stored in non-adjacent storage locations in the memory array. When the plurality of bits takes the form of an ECC word, the storage of bits in non-adjacent storage locations in the memory array reduces the likelihood of an uncorrectable multi-bit error. In another preferred embodiment, a memory device is provided comprising a memory array and a register comprising a first set of wordlines and bitlines and a second set of wordlines and bitlines arranged orthogonal to the first set.

Abstract: The preferred embodiments described herein provide a memory device and methods for use therewith. In one preferred embodiment, a method is presented for using a file system to dynamically respond to variability in an indicated minimum number of memory cells of first and second write-once memory devices. In another preferred embodiment, a method for overwriting data in a memory device is described in which an error code is disregarded after a destructive pattern is written. In yet another preferred embodiment, a method is presented in which, after a block of memory has been allocated for a file to be stored in a memory device, available lines in that block are determined. Another preferred embodiment relates to reserving at least one memory cell in a memory device for file structures or file system structures. A memory device is also provided in which file system structures of at least two file systems are stored in the same memory partition.

Abstract: The invention provides for a nonvolatile memory cell comprising a dielectric material in series with a phase change material, such as a chalcogenide. Phase change is achieved in chalcogenide memories by thermal means. Concentrating thermal energy in a relatively small volume assists this phase change. By applying high voltage across a dielectric layer, dielectric breakdown occurs, forming a low-resistance rupture region traversing the dielectric layer. This rupture region can serve to concentrate thermal energy in a phase-change memory cell. In a preferred embodiment, such a cell can be used in a monolithic three dimensional memory array.

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: Aspects of the present invention provide for a novel photomask for patterning features for an integrated circuit, the photomask including masked features having interior nonprinting windows. In some embodiments, the interior nonprinting window is an alternating phase shifter, while the area surrounding the masked features transmits light unshifted. In other embodiments, the interior nonprinting window transmits light unshifted, while the area surrounding the masked features is an alternating phase shifter. Thus any arrangement of features can be patterned with no phase conflict.

Abstract: A die is formed with different and optimized critical dimensions in different device levels and areas of those device levels using photolithography and etch techniques. One aspect of the invention provides for a memory array formed above a substrate, with driver circuitry formed in the substrate. A level of the memory array consists of, for example, parallel rails and a fan-out region. It is desirable to maximize density of the rails and minimize cost of lithography for the entire memory array. This can be achieved by forming the rails at a tighter pitch than the CMOS circuitry beneath it, allowing cheaper lithography tools to be used when forming the CMOS, and similarly by optimizing lithography and etch techniques for a device level to produce a tight pitch in the rails, and a more relaxed pitch in the less-critical fan-out region.