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Chung H. Lam, Peekskill US

Chung H. Lam, Peekskill, NY US

Patent application numberDescriptionPublished
20080248624METHOD OF MAKING INTEGRATED CIRCUIT (IC) INCLUDING AT LEAST ONE STORAGE CELL - A storage cell, integrated circuit (IC) chip with one or more storage cells that may be in an array of the storage cells and a method of forming the storage cell and IC. Each storage cell includes a stylus, the tip of which is phase change material. The phase change tip may be sandwiched between an electrode and conductive material, e.g., titanium nitride (TiN), tantalum nitride (TaN) or n-type semiconductor. The phase change layer may be a chalcogenide and in particular a germanium (Ge), antimony (Sb), tellurium (Te) (GST) layer.10-09-2008
20080251778FOUR-TERMINAL PROGRAMMABLE VIA-CONTAINING STRUCTURE AND METHOD OF FABRICATING SAME - A semiconductor structure that includes two programmable vias each of which contains a phase change material that is integrated with a heating material. In particular, the present invention provides a structure in which two programmable vias, each containing a phase change material, are located on opposing surfaces of a heating material. Each end portion of an upper surface of the heating material is connected to a metal terminal. These metal terminals, which are in contact with the end portions of the upper surface of the heating material, can be each connected to an outside component that controls and switches the resistance states of the two programmable vias. The two programmable vias of the inventive structure are each connected to another metal terminal. These metal terminals that are associated with the programmable vias can be also connected to a circuit block that may be present in the structure.10-16-2008
20080277644SWITCH ARRAY CIRCUIT AND SYSTEM USING PROGRAMMABLE VIA STRUCTURES WITH PHASE CHANGE MATERIALS - The present invention provides at least one programmable via structure that includes at least two phase change material vias that are both directly contacting a heating element, the programmable via structure further including a first terminal in contact with a first portion of the heating element, a second terminal in contact with a second portion of the heating element, a third terminal in contact with one of the at least two programmable vias, and a fourth terminal in contact with another one of the at least two programmable vias; a first circuit block in contact with one of the third and fourth terminals; a second circuit block in contact with the third or fourth terminal not contacting the first circuit block; a source region of a first field effect transistor in contact with one of the first and second terminals; and a drain region of a second field effect transistor in contact with the first or second terminal that is not contacting the source region of the first field effect transistor. A method of operating the at least one programmable via structure is also provided.11-13-2008
20080286905Fin-Type Antifuse - A method of forming an antifuse forms a material layer and then patterns the material layer into a fin. The center portion of the fin is converted into a substantially non-conductive region and the end portions of the fin into conductors. The process of converting the center portion of the fin into an insulator allows a process of heating the fin above a predetermined temperature to convert the insulator into a conductor. Thus, the fin-type structure that can be selectively converted from an insulator into a permanent conductor using a heating process.11-20-2008
20080299731ERASEABLE NONVOLATILE MEMORY WITH SIDEWALL STORAGE - A nonvolatile storage cell, integrated circuit (IC) including the cells and method of manufacturing the cells. A layered spacer (ONO) is formed at least at one sidewall of cell gates. Source/drain diffusions at each layered spacer underlap the adjacent gate. Charge may be stored at a layer (an imbedded nitride layer) in the layered spacer.12-04-2008
20090013146METHOD TO CREATE A UNIFORMLY DISTRIBUTED MULTI-LEVEL CELL (MLC) BITSTREAM FROM A NON-UNIFORM MLC BITSTREAM - A method, system, and computer software product for operating a collection of memory cells. Each memory cell in the collection of memory cells is configured to store a binary multi-bit value delimited by characteristic parameter bands. In one embodiment, a transforming unit transforms an original collection of data to a transformed collection of data using a reversible mathematical operator. The original collection of data has binary multi-bit values arbitrarily distributed across the binary multi-bit values assigned to the characteristic parameter bands and the transformed collection of data has binary multi-bit values substantially uniformly distributed across the binary multi-bit values assigned to the characteristic parameter bands.01-08-2009
20090013223MULTI-BIT ERROR CORRECTION SCHEME IN MULTI-LEVEL MEMORY STORAGE SYSTEM - A method, system, and computer software product for operating a collection of memory cells. Memory cells are organized into a group of memory cells, with each memory cell storing a binary multi-bit value delimited by characteristic parameter bands. Two adjacent characteristic parameter bands are assigned binary multi-bit values that differ by only one bit. In one embodiment, an error correction unit calculates an actual parity check value of the retrieved binary multi-bit values for the group of memory cells. If the actual parity check value is not equal to the expected parity check value, the error correction unit assigns the error memory cell a corrected binary multi-bit value with the characteristic parameter value within the characteristic parameter band adjacent to the characteristic parameter band associated with the retrieved binary multi-bit value such that calculating a second actual parity check value correctly indicates the parity for the group of memory cells.01-08-2009
20090013231Multi-bit error correction scheme in multi-level memory storage system - A method, system, and computer software product for operating a memory cell collection. Memory cells in the collection store binary multi-bit values delimited by characteristic parameter bands of a characteristic parameter. In one embodiment, a comparing unit compares a retrieved count and a stored count for each binary multi-bit value. The retrieved count, equal to the number of occurrences the binary multi-bit value, is retrieved from the memory cell collection. The stored count, equal to the number of occurrences the binary multi-bit value, is stored in the memory cell collection. An error correction unit then assigns the error memory cell(s) a corrected binary multi-bit value with the characteristic parameter value within the characteristic parameter band adjacent to the characteristic parameter band associated with the retrieved binary multi-bit value such that the retrieved count of each binary multi-bit value is equal to the stored count of each binary multi-bit value.01-08-2009
20090039331PHASE CHANGE MATERIAL STRUCTURES - Structures including a phase change material are disclosed. The structure may include a first electrode; a second electrode; a phase change material electrically connecting the first electrode and the second electrode for passing a current therethrough; and a tantalum nitride heater layer about the phase change material for converting the phase change material between an amorphous, insulative state and a crystalline, conductive state by application of a second current to the phase change material. The structure may be used as a fuse or a phase change material random access memory (PRAM).02-12-2009
20090045388PHASE CHANGE MATERIAL STRUCTURE AND RELATED METHOD - A structure including a phase change material and a related method are disclosed. The structure may include a first electrode; a second electrode; a third electrode; a phase change material electrically connecting the first, second and third electrodes for passing a first current through two of the first, second and third electrodes; and a refractory metal barrier heater layer about the phase change material for converting the phase change material between an amorphous, insulative state and a crystalline, conductive state by application of a second current to the phase change material. The structure may be used as a fuse or a phase change material random access memory (PRAM).02-19-2009
20090073783MULTI-LEVEL MEMORY CELL UTILIZING MEASUREMENT TIME DELAY AS THE CHARACTERISTIC PARAMETER FOR LEVEL DEFINITION - A memory array and computer program product for operating a memory cell and memory array. An embodiment of the invention entails receiving a request to read a binary value stored in the memory cell. A pre-charging operation pre-charges a bit-line capacitor in an electronic circuit formed by the memory cell to a pre-charge voltage. A word-line in the electronic circuit is then activated. A discharging operation discharges the bit-line capacitor through the said memory cell in the electronic circuit to the word-line. Additionally, an electron discharge time measurement is started when the word-line is activated. The electron discharge time measurement is stopped when the voltage level in the bit-line falls below a pre-defined reference voltage. A determining operation determines the binary value from the measured electron discharge time.03-19-2009
20090073784MULTI-LEVEL MEMORY CELL UTILIZING MEASUREMENT TIME DELAY AS THE CHARACTERISTIC PARAMETER FOR LEVEL DEFINITION - A memory array and computer program product for operating a memory cell and memory array. An embodiment of the invention entails receiving a binary value to be stored by a memory cell. A determining operation determines a target discharge time corresponding to the binary value. The target discharge time being the time needed to discharge a pre-charged circuit through the said memory cell to a predetermined level. A storing operation stores a characteristic parameter in the memory cell such that an electron discharge time through an electronic circuit formed, at least partially, by the memory cell, is substantially equal to the target discharge time.03-19-2009
20090073790MULTI-LEVEL MEMORY CELL UTILIZING MEASUREMENT TIME DELAY AS THE CHARACTERISTIC PARAMETER FOR LEVEL DEFINITION - A method for operating a memory cell and memory array. The method of memory cell operation entails receiving a request to read a binary value stored in the memory cell. A pre-charging operation pre-charges a bit-line capacitor in an electronic circuit formed by the memory cell to a pre-charge voltage. A word-line in the electronic circuit is then activated. A discharging operation discharges the bit-line capacitor through the said memory cell in the electronic circuit to the word-line. Additionally, an electron discharge time measurement is started when the word-line is activated. The electron discharge time measurement is stopped when the voltage level in the bit-line falls below a pre-defined reference voltage. A determining operation determines the binary value from the measured electron discharge time.03-19-2009
20090111228SELF ALIGNED RING ELECTRODES - The present invention in one embodiment provides a method of manufacturing an electrode that includes providing at least one metal stud positioned in a via extending into a first dielectric layer, wherein an electrically conductive liner is positioned between at least a sidewall of the via and the at least one metal stud; recessing an upper surface of the at least one metal stud below an upper surface of the first dielectric layer to provide at least one recessed metal stud; and forming a second dielectric atop the at least one recessed metal stud, wherein an upper surface of the electrically conductive liner is exposed.04-30-2009
20090173928POLYSILICON EMITTER BJT ACCESS DEVICE FOR PCRAM - A resistive non-volatile memory cell with a bipolar junction transistor (BJT) access device formed in conjunction with the entire memory cell. The memory cell includes a substrate acting as a collector, a semiconductor base layer acting as a base, and a semiconductor emitter layer acting as an emitter. Additionally, metal plugs and the phase change memory element are formed above the BJT access device while the emitter, metal plugs, and phase change memory element are contained within an insulating region. In one embodiment of the invention, a spacer layer is formed and the emitter layer is contained within the protective spacer layer. The spacer layer is contained within the insulating region.07-09-2009
20090186485SUB-LITHOGRAPHIC PRINTING METHOD - A method to form sub-lithographic trench structures in a substrate and an integrated circuit comprising sub-lithographic trench structures in a substrate. The method includes forming sets of trenches with a lithographic mask and filling the sets of trenches with sets of step spacer blocks comprising two alternating spacer materials which are separately removable from each other. In one embodiment, the trench structures formed are one-nth the thickness of the lithographic mask's feature size. The size of the trench structures being dependent on the thickness and number of spacer material layers used to form the set of step spacer blocks. The number of spacer material layers being n/2 and the thickness of each spacer material layer being one-nth of the lithographic mask's feature size.07-23-2009
20090189139PORE PHASE CHANGE MATERIAL CELL FABRICATED FROM RECESSED PILLAR - A method of manufacturing an electrode is provided that includes providing a pillar of a first phase change material atop a conductive structure of a dielectric layer; or the inverted structure; forming an insulating material atop dielectric layer and adjacent the pillar, wherein an upper surface of the first insulating material is coplanar with an upper surface of the pillar; recessing the upper surface of the pillar below the upper surface of the insulating material to provide a recessed cavity; and forming a second phase change material atop the recessed cavity and the upper surface of the insulating material, wherein the second phase change material has a greater phase resistivity than the first phase change material.07-30-2009
20090189731CROSS POINT SWITCH USING PHASE CHANGE MATERIAL - A cross-point switch and cross-point switch fabric utilizing phase change material, and method of operating the same. The cross-point switch includes a phase change cross-point circuit containing a plurality of terminal nodes connected to a central node. The connections between the terminal nodes and the central nodes are regulated by phase change switches comprised of a phase change material. The phase change switches being controlled by heating elements capable of melting or crystallizing the phase change material in the phase change switch. The heating elements are operated by a separate heating circuit. Each individual heating element is regulated by an individual transistor.07-30-2009
20090194757PHASE CHANGE ELEMENT EXTENSION EMBEDDED IN AN ELECTRODE - The present invention in one embodiment provides a method of forming a memory device that includes providing an interlevel dielectric layer including a conductive stud having a first width; forming an stack comprising a metal layer and a first insulating layer; forming a second insulating layer atop portions of the interlevel dielectric layer adjacent each sidewall of the stack; removing the first insulating layer to provide a cavity; forming a conformal insulating layer atop the second insulating layer and the cavity; applying an anisotropic etch step to the conformal insulating layer to produce a opening having a second width exposing an upper surface of the metal layer, wherein the first width is greater than the second width; and forming a memory material layer in the opening.08-06-2009
20090212272SELF-CONVERGING BOTTOM ELECTRODE RING - A method and memory cell including self-converged bottom electrode ring. The method includes forming a step spacer, a top insulating layer, an intermediate insulating layer, and a bottom insulating layer above a substrate. The method includes forming a step spacer within the top insulating layer and the intermediate insulating layer. The step spacer size is easily controlled. The method also includes forming a passage in the bottom insulating layer with the step spacer as a mask. The method includes forming bottom electrode ring within the passage comprising a cup-shaped outer conductive layer within the passage and forming an inner insulating layer within the cup-shaped outer conductive layer. The method including forming a phase change layer above the bottom electrode ring and a top electrode above the bottom electrode ring.08-27-2009
20090212274PHASE CHANGE MEMORY RANDOM ACCESS DEVICE USING SINGLE-ELEMENT PHASE CHANGE MATERIAL - A phase change memory cell with a single element phase change thin film layer; and a first electrode and a second electrode coupled to the single element phase change thin film layer. A current flows from the first electrode to the single element phase change thin film layer, and through to the second electrode. The single element phase change thin film layer includes a single element phase change material. The single element phase change thin film layer can be less than 5 nanometers thick. The temperature of crystallization of the single element phase change material can be controlled by its thickness. In one embodiment, the single element phase change thin film layer is configured to be amorphous at room temperature (25 degrees Celsius). In one embodiment, the single element phase change thin film layer is comprised of Antimony (Sb).08-27-2009
20090230377Phase Change Materials for Applications that Require Fast Switching and High Endurance - A memory device utilizing a phase change material as the storage medium, the phase change material based on antimony as the solvent in a solid solution; wherein the memory device further includes a means for heating the phase change material.09-17-2009
20090268507PHASE CHANGE MEMORY DEVICE AND METHOD OF MANUFACTURE - A phase change memory control ring lower electrode is disclosed. The lower electrode includes an outer ring electrode in thermal contact with a phase change memory element, an inner seed layer disposed within the outer ring electrode and in contact with the phase change memory element, and an electrically conductive bottom layer coupled to the outer ring electrode.10-29-2009
20090275168PHASE CHANGE MATERIAL WITH FILAMENT ELECTRODE - The present invention, in one embodiment, provides a memory device that includes a phase change memory cell; a first electrode; and a layer of filamentary resistor material positioned between the phase change memory cell and the first electrode, wherein at least one bistable conductive filamentary pathway is present in at least a portion of the layer of filamentary resistor material that provides electrical communication between the phase change memory cell and the first electrode.11-05-2009
20090294850METHOD TO TAILOR LOCATION OF PEAK ELECTRIC FIELD DIRECTLY UNDERNEATH AN EXTENSION SPACER FOR ENHANCED PROGRAMMABILITY OF A PROMPT-SHIFT DEVICE - The invention provides a method to enhance the programmability of a prompt-shift device, which reduces the programming time to sub-millisecond times, by altering the extension and halo implants, instead of simply omitting the same from one side of the device as is the case in the prior art prompt-shift devices. The invention includes an embodiment in which no additional masks are employed, or one additional mask is employed. The altered extension implant is performed at a reduced ion dose as compared to a conventional extension implant process, while the altered halo implant is performed at a higher ion dose than a conventional halo implant. The altered halo/extension implant shifts the peak of the electrical field to under an extension dielectric spacer.12-03-2009
20090298223SELF-ALIGNED IN-CONTACT PHASE CHANGE MEMORY DEVICE - A memory cell and a method of making the same, that includes insulating material deposited on a substrate, a bottom electrode formed within the insulating material, a plurality of insulating layers deposited above the bottom electrode and at least one of which acts as an intermediate insulating layer. Then defining a via in the insulating layers above the intermediate insulating layer, creating a channel for etch with a step spacer, defining a pore in the intermediate insulating layer, removing all insulating layers above the intermediate insulating layer, filling the entirety of the pore with phase change material, and forming an upper electrode above the phase change material. Additionally, the formation of bit line connections with the upper electrode.12-03-2009
20090303786SWITCH ARRAY CIRCUIT AND SYSTEM USING PROGRAMMABLE VIA STRUCTURES WITH PHASE CHANGE MATERIALS - The present invention provides at least one programmable via structure that includes at least two phase change material vias that are both directly contacting a heating element, the programmable via structure further including a first terminal in contact with a first portion of the heating element, a second terminal in contact with a second portion of the heating element, a third terminal in contact with one of the at least two programmable vias, and a fourth terminal in contact with another one of the at least two programmable vias; a first circuit block in contact with one of the third and fourth terminals; a second circuit block in contact with the third or fourth terminal not contacting the first circuit block; a source region of a first field effect transistor in contact with one of the first and second terminals; and a drain region of a second field effect transistor in contact with the first or second terminal that is not contacting the source region of the first field effect transistor. A method of operating the at least one programmable via structure is also provided.12-10-2009
20090305492VERTICAL FIELD EFFECT TRANSISTOR ARRAYS AND METHODS FOR FABRICATION THEREOF - Vertical field effect transistor semiconductor structures and methods for fabrication of the vertical field effect transistor semiconductor structures provide an array of semiconductor pillars. Each vertical portion of each semiconductor pillar in the array of semiconductor pillars has a linewidth greater than a separation distance to an adjacent semiconductor pillar. Alternatively, the array may comprise semiconductor pillars with different linewidths, optionally within the context of the foregoing linewidth and separation distance limitations. A method for fabricating the array of semiconductor pillars uses a minimally photolithographically dimensioned pillar mask layer that is annularly augmented with at least one spacer layer prior to being used as an etch mask.12-10-2009
20090305508INTEGRATED CIRCUIT WITH UPSTANDING STYLUS - A stylus, an integrated circuit (IC) and method of forming the IC. The stylus extends upward from its apex and has a substantially circular cross section that decreases in diameter upward from the apex. The stylus is formed in a mold that may be formed in an orifice in a dielectric layer between wiring layers. The mold may include multiple concentric layers. For a more pronounced, non-linear stylus taper, each layer may be thinner than its next adjacent outer concentric layer.12-10-2009
20090311858PROGRAMMABLE VIA STRUCTURE AND METHOD OF FABRICATING SAME - A programmable via structure is provided as well as a method of fabricating the same. The inventive programmable via a semiconductor substrate. An oxide layer such as a thermal oxide is located on a surface of the semiconductor substrate. A patterned heating material is located on a surface of the oxide layer. The inventive structure also includes a patterned dielectric material having a least one via filled with a phase change material (PCM). The patterned dielectric material including the PCM filled via is located on a surface of the patterned heating material. A patterned diffusion barrier is located on an exposed surface of said at least one via filled with the phase change material. The inventive structure also includes contact vias that extend through the patterned dielectric material. The contact vias are filled with a conductive material which also extends onto the upper surface of the patterned dielectric material. A conductive material which serves as the input of the device is located atop the patterned diffusion barrier that is located directly above the via that is filled with the phase change material.12-17-2009
20100002481CONTENT ADDRESSABLE MEMORY USING PHASE CHANGE DEVICES - Content addressable memory device utilizing phase change devices. An aspect of the content addressable memory device is the use of a comparatively lower power search-line access element and a comparatively higher power word-line access element. The word-line access element is only utilized during write operations and the search-line access element is only utilized during search operations. The word-line access element being electrically coupled to a second end of a phase change memory element and a word-line. The search-line access element also being electrically coupled to the second end of the phase change memory element and a search-line. The search-line being electrically coupled to a match-line. A bit-line is electrically coupled to a first end of the phase change memory element. Additionally, a complementary set of access elements, a complementary phase change memory element, a complementary search-line, and a complementary bit-line are also included in the content addressable memory device.01-07-2010
20100002499PHASE CHANGE MEMORY PROGRAMMING METHOD WITHOUT RESET OVER-WRITE - A method for programming a phase change memory device that avoids RESET overwrite. The method partially comprised of applying a reset write current pulse through the phase change memory element such that the reset write current pulse produces a voltage drop across the phase change memory element less than a reset threshold voltage and greater than a set threshold voltage. The reset write current pulse writing a RESET state to the phase change memory cell. The method additionally comprised of applying a set write current pulse through the phase change memory element such that the set write current pulse produces a voltage drop across the phase change memory element that is equal to or greater than the reset threshold voltage. The set write current pulse writing a SET state to the phase change memory cell.01-07-2010
20100048020Nanoscale Electrodes for Phase Change Memory Devices - A process for preparing a phase change memory semiconductor device comprising a (plurality of) nanoscale electrode(s) for alternately switching a chalcogenide phase change material from its high resistance (amorphous) state to its low resistance (crystalline) state, whereby a reduced amount of current is employed, and wherein the plurality of nanoscale electrodes, when present, have substantially the same dimensions.02-25-2010
20100078617METHOD TO REDUCE A VIA AREA IN A PHASE CHANGE MEMORY CELL - A memory cell structure and method to form such structure. The method partially comprised of forming a via within an oxidizing layer, over the center of a bottom electrode. The method includes depositing a via spacer along the sidewalls of the via and oxidizing the via spacer. The via spacer being comprised of a material having a Pilling-Bedworth ratio of at least one and one-half and is an insulator when oxidized. The via area is reduced by expansion of the via spacer during the oxidation. Alternatively, the method is partially comprised of forming a via within a first layer, over the center of the bottom electrode. The first layer has a Pilling-Bedworth ratio of at least one and one-half and is an insulator when oxidized. The method also includes oxidizing at least a portion of the sidewalls of the via in the first layer.04-01-2010
20100078621METHOD TO REDUCE RESET CURRENT OF PCM USING STRESS LINER LAYERS - A memory cell structure and method for forming the same. The method includes forming a via within a dielectric layer. The via is formed over the center of an electrically conducting bottom electrode. The method includes depositing a stress liner along at least one sidewall of the via. The stress liner imparting stress on material proximate the stress liner. In one embodiment, the stress liner provides a stress in the range of 500 to 5000 MPa on the material enclosed within its volume. The method includes depositing phase change material within the via and the volume enclosed by the stress liner. The method also includes forming an electrically conducting top electrode above the phase change material.04-01-2010
20100135085MULTI-LEVEL MEMORY CELL UTILIZING MEASUREMENT TIME DELAY AS THE CHARACTERISTIC PARAMETER FOR LEVEL DEFINITION - A computer program product for operating a memory cell and memory array. The computer program product of memory cell operation entails receiving a request to read a binary value stored in the memory cell. A pre-charging operation pre-charges a bit-line capacitor in an electronic circuit formed by the memory cell to a pre-charge voltage. A word-line in the electronic circuit is then activated. A discharging operation discharges the bit-line capacitor through the said memory cell in the electronic circuit to the word-line. Additionally, an electron discharge time measurement is started when the word-line is activated. The electron discharge time measurement is stopped when the voltage level in the bit-line falls below a pre-defined reference voltage. A determining operation determines the binary value from the measured electron discharge time.06-03-2010
20100176362POLYSILICON PLUG BIPOLAR TRANSISTOR FOR PHASE CHANGE MEMORY - Memory devices and methods for manufacturing are described herein. A memory device described herein includes a plurality of memory cells. Memory cells in the plurality of memory cells comprise respective bipolar junction transistors and memory elements. The bipolar junction transistors are arranged in a common collector configuration and include an emitter comprising doped polysilicon having a first conductivity type, the emitter contacting a corresponding word line in a plurality of word lines to define a pn junction. The bipolar junction transistors include a portion of the corresponding word line underlying the emitter acting as a base, and a collector comprising a portion of the single-crystalline substrate underlying the base.07-15-2010
20100181649POLYSILICON PILLAR BIPOLAR TRANSISTOR WITH SELF-ALIGNED MEMORY ELEMENT - Memory cells having memory elements self-aligned with the emitters of bipolar junction transistor access devices are described herein, as well as methods for manufacturing such devices. A memory device as described herein comprises a plurality of memory cells. Memory cells in the plurality of memory cells include a bipolar junction transistor comprising an emitter comprising a pillar of doped polysilicon. The memory cells include an insulating element over the emitter and having an opening extending through the insulating layer, the opening centered over the emitter. The memory cells also include a memory element within the opening and electrically coupled to the emitter.07-22-2010
20100214811CODING TECHNIQUES FOR IMPROVING THE SENSE MARGIN IN CONTENT ADDRESSABLE MEMORIES - A content addressable memory using encoded data words and search words, and techniques for operating such device. In one embodiment, the data word is transformed into a code word guaranteeing a mismatch of at least two code word bits of different binary values during the memory search operation when the data word does not match a search word. In another embodiment, the search word is transformed into a search code such that the Hamming distance between the code word and the search code is greater than a given threshold when there is a mismatch of at least one bit between the data word and the search word.08-26-2010
20100226161TERNARY CONTENT ADDRESSABLE MEMORY USING PHASE CHANGE DEVICES - A content addressable memory device with a plurality of memory cells storing ternary data values of high, low, and don't care. An aspect of the content addressable memory device is the use of first memory elements and second memory elements in the memory cells. The first and second memory elements are electrically coupled in parallel circuit to a match-line. The first memory elements are coupled to first word-lines and the second memory elements are coupled to second word-lines. The first memory elements are configured to store low resistance states if the ternary data value is low and high resistance states if the ternary data value is either high or don't care. The second memory elements are configured to store the low resistance states if the ternary data value is high and the high resistance states if the ternary data value is either low or don't care.09-09-2010
20100265748HIGH DENSITY TERNARY CONTENT ADDRESSABLE MEMORY - A content addressable memory device with a plurality of memory cells storing data words. Each data bit in the data words is set to one of three values of a first binary value, a second binary value, and a don't care value. An aspect of the content addressable memory device is the use of a single memory element and an access device in the memory cells. The memory cells are arranged such that each memory cell is electrically coupled to a single bit line, a single match line, and a single word line. The memory elements in the memory cells store low resistance states if the data bit value is the first binary value, high resistance states if the data bit value is the second binary value, and very high resistance states if the data bit value is the don't care value.10-21-2010
20100295009Phase Change Memory Cells Having Vertical Channel Access Transistor and Memory Plane - Memory devices are described along with methods for manufacturing. A memory device as described herein comprises a plurality of word lines overlying a plurality of bit lines, and a plurality of field effect transistors. Field effect transistors in the plurality of field effect transistors comprises a first terminal electrically coupled to a corresponding bit line in the plurality of bit lines, a second terminal overlying the first terminal, and a channel region separating the first and second terminals and adjacent a corresponding word line in the plurality of word lines. The corresponding word line acts as the gate of the field effect transistor. A dielectric separates the corresponding word line from the channel region. A memory plane comprises programmable resistance memory material electrically coupled to respective second terminals of the field effect transistors, and conductive material on the programmable resistance memory material and coupled to a common voltage.11-25-2010
20100295123Phase Change Memory Cell Having Vertical Channel Access Transistor - Memory devices are described along with methods for manufacturing. A device as described herein includes a substrate having a first region and a second region. The first region comprises a first field effect transistor comprising first and second doped regions separated by a horizontal channel region within the substrate, a gate overlying the horizontal channel region, and a first dielectric covering the gate of the first field effect transistor. The second region of the substrate includes a second field effect transistor comprising a first terminal extending through the first dielectric to contact the substrate, a second terminal overlying the first terminal and having a top surface, and a vertical channel region separating the first and second terminals. The second field effect transistor also includes a gate on the first dielectric and adjacent the vertical channel region, the gate having a top surface that is co-planar with the top surface of the second terminal. A second dielectric separates the gate of the second field effect transistor from the vertical channel region.11-25-2010
20100301409VERTICAL FIELD EFFECT TRANSISTOR ARRAYS AND METHODS FOR FABRICATION THEREOF - Vertical field effect transistor semiconductor structures and methods for fabrication of the vertical field effect transistor semiconductor structures provide an array of semiconductor pillars. Each vertical portion of each semiconductor pillar in the array of semiconductor pillars has a linewidth greater than a separation distance to an adjacent semiconductor pillar. Alternatively, the array may comprise semiconductor pillars with different linewidths, optionally within the context of the foregoing linewidth and separation distance limitations. A method for fabricating the array of semiconductor pillars uses a minimally photolithographically dimensioned pillar mask layer that is annularly augmented with at least one spacer layer prior to being used as an etch mask.12-02-2010
20100328994PHASE CHANGE MEMORY WITH FINITE ANNULAR CONDUCTIVE PATH - A phase change memory device and a method for programming the same. The method includes determining a maximum possible resistance for the memory cells in the phase change memory device. The method includes determining a high resistance state for the memory cells in the phase change memory device. The method includes receiving a request to program a target memory cell in the phase change memory device to the high resistance state. The method also includes resetting the target memory cell in the phase change memory device to the high resistance state such that the high resistance state of the target memory cell is of less resistance than the maximum possible resistance. In one embodiment of the invention, the high resistance state for the memory cells in the phase change memory device is at least 10% less than the maximum possible resistance.12-30-2010
20110001111THERMALLY INSULATED PHASE CHANGE MATERIAL CELLS - A memory cell structure and method for forming the same. The method includes forming a pore within a dielectric layer. The pore is formed over the center of an electrically conducting bottom electrode. The method includes depositing a thermally insulating layer along at least one sidewall of the pore. The thermally insulating layer isolates heat from phase change current to the volume of the pore. In one embodiment phase change material is deposited within the pore and the volume of the thermally insulating layer. In another embodiment a pore electrode is formed within the pore and the volume of the thermally insulating layer, with the phase change material being deposited above the pore electrode. The method also includes forming an electrically conducting top electrode above the phase change material.01-06-2011
20110049460SINGLE MASK ADDER PHASE CHANGE MEMORY ELEMENT - A method of fabricating a phase change memory element within a semiconductor structure includes etching an opening to an upper surface of a bottom electrode, the opening being formed of a height equal to a height of a metal region at a same layer within the semiconductor structure, depositing phase change material within the opening, recessing the phase change material within the opening, and forming a top electrode on the recessed phase change material.03-03-2011
20110049461CHEMICAL MECHANICAL POLISHING STOP LAYER FOR FULLY AMORPHOUS PHASE CHANGE MEMORY PORE CELL - A method for fabricating a phase change memory pore cell that includes forming a bottom electrode, forming a first dielectric layer on the bottom electrode, forming a sacrificial layer on the first dielectric layer, forming an isolation layer on the sacrificial layer, and forming a second dielectric layer on the isolation layer. The method further includes forming a via overlying the bottom electrode, the via extending to the sacrificial layer, etching through the sacrificial layer to the first dielectric layer to form a pore defined extending through the sacrificial layer and the first dielectric layer, depositing phase change material on the sacrificial layer and into the pore and removing the phase change material formed outside the pore, removing the sacrificial layer to expose the pore, the pore being vertically aligned, and forming a top electrode over the pore.03-03-2011
20110049462FLAT LOWER BOTTOM ELECTRODE FOR PHASE CHANGE MEMORY CELL - A phase change memory cell having a flat lower bottom electrode and a method for fabricating the same. The method includes forming a dielectric layer over a substrate including an array of conductive contacts, patterning, a via having a low aspect ratio such that a depth of the via is less than a width thereof, to a contact surface of the substrate corresponding to each of the array of conductive contacts to be connected to access circuitry, etching the dielectric layer and depositing electrode material over the etched dielectric layer and within each via, and planarizing the electrode material to form a plurality of lower bottom electrodes on each of the conductive contacts.03-03-2011
20110057162IN VIA FORMED PHASE CHANGE MEMORY CELL WITH RECESSED PILLAR HEATER - A method for fabricating a phase change memory device including a plurality of in via phase change memory cells includes forming pillar heaters formed of a conductive material along a contact surface of a substrate corresponding to each of an array of conductive contacts to be connected to access circuitry, forming a dielectric layer along exposed areas of the substrate surrounding the pillar heaters, forming an interlevel dielectric (ILD) layer above the dielectric layer, etching a via to the dielectric layer, each via corresponding to each of pillar heater such that an upper surface of each pillar heater is exposed within each via, recessing each pillar heater, depositing phase change material in each via on each recessed pillar heater, recessing the phase change material within each via, and forming a top electrode within the via on the phase change material.03-10-2011
20110069538MULTI-LEVEL CELL PROGRAMMING OF PCM BY VARYING THE RESET AMPLITUDE - A phase change memory device and a method for programming the same. The method includes determining a characterized lowest SET current and corresponding SET resistance for the phase change memory device. The method includes determining a characterized RESET current slope for the phase change memory device. The method also includes calculating a first current amplitude for a RESET pulse based on the characterized lowest SET current and the characterized RESET current slope. The method includes applying the RESET pulse to a target memory cell in the phase change memory device and measuring the resistance of the target memory cell. If the measured resistance is substantially less than a target resistance, the method further includes applying one or more additional RESET pulses. In one embodiment of the invention, the one or more additional RESET pulses have current amplitudes greater than a previously applied RESET pulse.03-24-2011
20110104899SUB-LITHOGRAPHIC PRINTING METHOD - A trench structure and an integrated circuit comprising sub-lithographic trench structures in a substrate. In one embodiment the trench structure is created by forming sets of trenches with a lithographic mask and filling the sets of trenches with sets of step spacer blocks comprising two alternating spacer materials which are separately removable from each other. In one embodiment, the trench structures formed are one-nth the thickness of the lithographic mask's feature size. The size of the trench structures being dependent on the thickness and number of spacer material layers used to form the set of step spacer blocks. The number of spacer material layers being n/2 and the thickness of each spacer material layer being one-nth of the lithographic mask's feature size.05-05-2011
20110108960SUB-LITHOGRAPHIC PRINTING METHOD - A trench structure and an integrated circuit comprising sub-lithographic trench structures in a substrate. In one embodiment the trench structure is created by forming sets of trenches with a lithographic mask and filling the sets of trenches with sets of step spacer blocks comprising two alternating spacer materials which are separately removable from each other. In one embodiment, the trench structures formed are one-nth the thickness of the lithographic mask's feature size. The size of the trench structures being dependent on the thickness and number of spacer material layers used to form the set of step spacer blocks. The number of spacer material layers being n/2 and the thickness of each spacer material layer being one-nth of the lithographic mask's feature size.05-12-2011
20110116312NON VOLATILE CELL AND ARCHITECTURE WITH SINGLE BIT RANDOM ACCESS READ, PROGRAM AND ERASE - One embodiment is a non-volatile memory cell with random access read, program, and erase. The memory cell includes a cell transistor that includes a source region, a drain region, a first insulating spacer, and a second insulating spacer. The memory cell also includes a source-side transistor, a drain-side transistor, a source-side multiplexer, a drain-side multiplexer, a source-side sense amplifier, and a drain-side write driver. A first binary value is stored in a first bit in the memory cell by trapping or releasing a first electric charge in the first insulating spacer. The first bit is read by sensing the resistive change in the cell transistor or by sensing the threshold voltage change in the cell transistor.05-19-2011

Patent applications by Chung H. Lam, Peekskill, NY US