Abstract: A nonvolatile memory cell includes a layer of a resistivity-switching metal oxide or nitride compound, the metal oxide or nitride compound including one metal, and a dielectric rupture antifuse formed in series. The dielectric rupture antifuse may be either in its initial, non-conductive state or a ruptured, conductive state. The resistivity-switching metal oxide or nitride layer can be in a higher- or lower-resistivity state. By using both the state of the resistivity-switching layer and the antifuse to store data, more than two bits can be stored per memory cell.
Abstract: By decreasing the amount of card substrate required in a memory card to support the actual memory unit, the test interface of the card, which is usually removed before final assembly of the card, can be brought within the allowable length of the finished card and can, therefore, remain on the card permanently. Consequently, in the event of a field failure, the test interface remains available for testing the card and diagnosing the location and cause of the failure.
Abstract: A monolithic, three dimensional NAND string includes a first memory cell located over a second memory cell. A semiconductor active region of the first memory cell is a first pillar having a square or rectangular cross section when viewed from above, the first pillar being a first conductivity type semiconductor region located between second conductivity type semiconductor regions. A semiconductor active region of the second memory cell is a second pillar having a square or rectangular cross section when viewed from above, the second pillar located under the first pillar, the second pillar being a first conductivity type semiconductor region located between second conductivity type semiconductor regions. One second conductivity type semiconductor region in the first pillar contacts one second conductivity type semiconductor region in the second pillar.
Abstract: Methods in accordance with aspects of this invention form microelectronic structures in accordance with other aspects this invention, such as non-volatile memories, that include (1) a bottom electrode, (2) a resistivity-switchable layer disposed above and in contact with the bottom electrode, and (3) a top electrode disposed above and in contact with the resistivity-switchable layer; wherein the resistivity-switchable layer includes a carbon-based material and a dielectric filler material. Numerous additional aspects are provided.
Abstract: A method of making a nonvolatile memory device includes forming a semiconductor diode steering element, and forming a semiconductor read/write switching element.
Abstract: A nonvolatile memory cell comprising a diode formed of semiconductor material can store memory states by changing the resistance of the semiconductor material by application of a set pulse (decreasing resistance) or a reset pulse (increasing resistance.) In preferred embodiments, set pulses are applied with the diode under forward bias, while reset pulses are applied with the diode in reverse bias. By switching resistivity of the semiconductor material of the diode, a memory cell can be either one-time programmable or rewriteable, and can achieve two, three, four, or more distinct data states.
Type:
Grant
Filed:
July 31, 2006
Date of Patent:
September 21, 2010
Assignee:
Sandisk 3D LLC
Inventors:
Tanmay Kumar, S. Brad Herner, Roy E Scheuerlein, Christopher J Petti
Abstract: A method of operating a nonvolatile memory cell includes providing the nonvolatile memory cell comprising a diode which is fabricated in a first resistivity, unprogrammed state, and applying a forward bias to the diode having a magnitude greater than a minimum voltage required for programming the diode to switch the diode to a second resistivity, programmed state. The second resistivity state is lower than the first resistivity state.
Type:
Grant
Filed:
June 25, 2007
Date of Patent:
September 21, 2010
Assignee:
Sandisk 3D LLC
Inventors:
Tanmay Kumar, S. Brad Herner, Christopher J. Petti
Abstract: A nonvolatile memory cell comprising doped semiconductor material and a diode can store memory states by changing the resistance of the doped semiconductor material by application of a set pulse (decreasing resistance) or a reset pulse (increasing resistance.) Set pulses are of short duration and above a threshold voltage, while reset pulses are longer duration and below a threshold voltage. In some embodiments multiple resistance states can be achieved, allowing for a multi-state cell, while restoring a prior high-resistance state allows for an rewriteable cell. In some embodiments, the diode and a switchable memory formed of doped semiconductor material are formed in series, while in other embodiments, the diode itself serves as the semiconductor switchable memory element.
Abstract: A voltage regulator is disclosed. The voltage regulator has a voltage generation circuit that outputs a regulated voltage and a load current. The voltage regulation circuit has a sensing circuit that senses a peak magnitude of the load current and stores a peak signal that is based on the peak load current magnitude. The sensing circuit receives at least one signal that is input to the voltage regulation circuit and senses the peak magnitude of the load current. The voltage regulation circuit has a current generation circuit that generates a compensation current that has a magnitude that is proportional to the peak load current magnitude. The current generation circuit generates the compensation current based on the peak signal. The compensation current is provided during a time interval that is defined by at least one signal that is input to the voltage regulation circuit.
Abstract: A method is described for forming a thin film transistor having its current-switching region in polycrystalline semiconductor material which has been crystallized in contact with titanium silicide, titanium silicide-germanide, or titanium germanide. The titanium silicide, titanium silicide-germanide, or titanium germanide is formed having feature size no more than 0.25 micron in the smallest dimension. The small feature size tends to inhibit the phase transformation from C49 to C54 phase titanium silicide. The C49 phase of titanium silicide has a very close lattice match to silicon, and thus provides a crystallization template for the silicon as it forms, allowing formation of large-grain, low-defect silicon. Titanium does not tend to migrate through the silicon during crystallization, limiting the danger of metal contamination. In preferred embodiments, the transistors thus formed may be, for example, field-effect transistors or bipolar junction transistors.
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.
Type:
Grant
Filed:
October 25, 2007
Date of Patent:
September 7, 2010
Assignee:
SanDisk 3D LLC
Inventors:
Samuel V. Dunton, Usha Raghuram, Christopher J. Petti
Abstract: Methods and apparatus are described that develop a reference voltage that is based on a difference between a threshold voltage of a first transistor and a threshold voltage of a second transistor, and further based on a difference between a gate overdrive voltage of the first transistor and a gate overdrive voltage of the second transistor.
Abstract: A method of making a semiconductor device includes forming at least one device layer over a substrate, forming at least two spaced apart features over the at least one device layer, forming sidewall spacers on the at least two features, selectively removing the spaced apart features, filling a space between a first sidewall spacer and a second sidewall spacer with a filler feature, selectively removing the sidewall spacers to leave a plurality of the filler features spaced apart from each other, and etching the at least one device layer using the filler feature as a mask.
Type:
Grant
Filed:
April 28, 2008
Date of Patent:
August 31, 2010
Assignee:
SanDisk 3D LLC
Inventors:
Yung-Tin Chen, Chun-Ming Wang, Steven J. Radigan, Christopher J. Petti, Steven Maxwell
Abstract: A method of making a semiconductor device includes forming at least one device layer over a substrate, forming a plurality of spaced apart first features over the device layer, where each three adjacent first features form an equilateral triangle, forming sidewall spacers on the first features, filling a space between the sidewall spacers with a plurality of filler features, selectively removing the sidewall spacers, and etching the at least one device layer using at least the plurality of filler features as a mask. A device contains a plurality of bottom electrodes located over a substrate, a plurality of spaced apart pillars over the plurality of bottom electrodes, and a plurality of upper electrodes contacting the plurality of pillars. Each three adjacent pillars form an equilateral triangle, and each pillar comprises a semiconductor device.
Type:
Grant
Filed:
June 30, 2008
Date of Patent:
August 24, 2010
Assignee:
Sandisk 3D LLC
Inventors:
Chun-Ming Wang, Yung-Tin Chen, Roy E. Scheuerlein
Abstract: A memory array having memory cells comprising a diode and an antifuse can be made smaller and programmed at lower voltage by using an antifuse material having a higher dielectric constant and a higher acceleration factor than those of silicon dioxide, and by using a diode having a lower band gap than that of silicon. Such memory arrays can be made to have long operating lifetimes by using the high acceleration factor and lower band gap materials. Antifuse materials having dielectric constants between 5 and 27, for example, hafnium silicon oxynitride or hafnium silicon oxide, are particularly effective. Diode materials with band gaps lower than that of silicon, such as germanium or a silicon-germanium alloy, are particularly effective.
Type:
Grant
Filed:
February 6, 2009
Date of Patent:
August 24, 2010
Assignee:
SanDisk 3D LLC
Inventors:
Xiaoyu Yang, Roy E. Scheurelein, Feng Li, Albert T. Meeks
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: Systems, methods, and apparatus are provided for thermal regulation of a non-volatile memory IC. The systems and apparatus may include a thermal sensor on a memory IC; and a heating element coupled to the thermal sensor and adapted to heat the memory IC in response to a signal from the thermal sensor. The methods may include sensing a temperature of a memory IC using an integrated thermal sensor on the memory IC and heating the memory IC, using an integrated heating element operatively coupled to the thermal sensor, if the sensed temperature is below a threshold temperature.
Abstract: The embodiments generally relate to methods of making semiconductor devices, and more particularly, to methods for making semiconductor pillar structures and increasing array feature pattern density using selective or directional gap fill. The technique has application to a variety of materials and can be applied to making monolithic two or three-dimensional memory arrays.
Type:
Application
Filed:
April 5, 2010
Publication date:
August 5, 2010
Applicant:
SanDisk 3D LLC
Inventors:
Huiwen Xu, Yung-Tin Chen, Steven J. Radigan
Abstract: A method to form a vertical interconnect advantageous for high-density semiconductor devices. A conductive etch stop layer, preferably of cobalt silicide, is formed. The etch stop layer may be in the form of patterned lines or wires. A layer of contact material is formed on and in contact with the etch stop layer. The layer of contact material is patterned to form posts. Dielectric is deposited over and between the posts, then the dielectric planarized to expose the tops of the posts. The posts can serve as vertical interconnects which electrically connect a next conductive layer formed on and in contact with the vertical interconnects with the underlying etch stop layer. The patterned dimension of vertical interconnects formed according to the present disclosure can be substantially the same as the minimum feature size, even at very small minimum feature size.
Abstract: A method is disclosed to form an upward-pointing p-i-n diode formed of deposited silicon, germanium, or silicon-germanium. The diode has a bottom heavily doped p-type region, a middle intrinsic or lightly doped region, and a top heavily doped n-type region. The top heavily doped p-type region is doped with arsenic, and the semiconductor material of the diode is crystallized in contact with an appropriate silicide, germanide, or silicide-germanide. A large array of such upward-pointing diodes can be formed with excellent uniformity of current across the array when a voltage above the turn-on voltage of the diodes is applied. This diode is advantageously used in a monolithic three dimensional memory array.