Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N70/00—Solid-state devices having no potential barriers, and specially adapted for rectifying, amplifying, oscillating or switching
  • H10N70/20—Multistable switching devices, e.g. memristors
  • H10N70/231—Multistable switching devices, e.g. memristors based on solid-state phase change, e.g. between amorphous and crystalline phases, Ovshinsky effect
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11C—STATIC STORES
  • G11C13/00—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00
  • G11C13/0002—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00 using resistive RAM [RRAM] elements
  • G11C13/0021—Auxiliary circuits
  • G11C13/0069—Writing or programming circuits or methods
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10B—ELECTRONIC MEMORY DEVICES
  • H10B63/00—Resistance change memory devices, e.g. resistive RAM [ReRAM] devices
  • H10B63/20—Resistance change memory devices, e.g. resistive RAM [ReRAM] devices comprising selection components having two electrodes, e.g. diodes
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N70/00—Solid-state devices having no potential barriers, and specially adapted for rectifying, amplifying, oscillating or switching
  • H10N70/011—Manufacture or treatment of multistable switching devices
  • H10N70/061—Shaping switching materials
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N70/00—Solid-state devices having no potential barriers, and specially adapted for rectifying, amplifying, oscillating or switching
  • H10N70/801—Constructional details of multistable switching devices
  • H10N70/821—Device geometry
  • H10N70/826—Device geometry adapted for essentially vertical current flow, e.g. sandwich or pillar type devices
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N70/00—Solid-state devices having no potential barriers, and specially adapted for rectifying, amplifying, oscillating or switching
  • H10N70/801—Constructional details of multistable switching devices
  • H10N70/841—Electrodes
  • H10N70/8413—Electrodes adapted for resistive heating
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N70/00—Solid-state devices having no potential barriers, and specially adapted for rectifying, amplifying, oscillating or switching
  • H10N70/801—Constructional details of multistable switching devices
  • H10N70/881—Switching materials
  • H10N70/882—Compounds of sulfur, selenium or tellurium, e.g. chalcogenides
  • H10N70/8828—Tellurides, e.g. GeSbTe
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11C—STATIC STORES
  • G11C13/00—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00
  • G11C13/0002—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00 using resistive RAM [RRAM] elements
  • G11C13/0021—Auxiliary circuits
  • G11C13/0069—Writing or programming circuits or methods
  • G11C2013/008—Write by generating heat in the surroundings of the memory material, e.g. thermowrite
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11C—STATIC STORES
  • G11C2213/00—Indexing scheme relating to G11C13/00 for features not covered by this group
  • G11C2213/50—Resistive cell structure aspects
  • G11C2213/52—Structure characterized by the electrode material, shape, etc.
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]

Definitions

• This invention relates generally to electronic memories and particularly to electronic memories that use phase change material.
• Phase change materials may exhibit at least two different states.
• the states may be called the amorphous and crystalline states. Transitions between these states may be selectively initiated.
• the states may be distinguished because the amorphous state generally exhibits higher resistivity than the crystalline state.
• the amorphous state involves a more disordered atomic structure.
• any phase change material may be utilized. In some embodiments, however, thin- film chalcogenide alloy materials may be particularly suitable.
• the phase change may be induced reversibly. Therefore, the memory may change from the amorphous to the crystalline state and may revert back to the amorphous state thereafter, or vice versa, in response to temperature changes.
• each memory cell may be thought of as a programmable resistor, which reversibly changes between higher and lower resistance states.
• the phase change may be induced by resistive heating.
• Existing phase change memories may experience inefficient heating of the phase change material. Thus, there is a need for better ways to heat phase change material.
• Figure 1 is an enlarged cross-sectional view of a portion of a phase change memory in accordance with one embodiment of the present invention
• Figure 2 is a schematic depiction of a system using a phase change memory in accordance with one embodiment of the present invention.
• a phase change memory 10 may include a plurality of phase change memory cells 12 including the adjacent cells 12a and 12b on adjacent bitlines 14. Each bitline 14 is positioned over a banier material 16.
• the barrier material 16 may extend into a pore 46 on top of the phase change material 18 which may be a chalcogenide material in one embodiment of the present invention.
• phase change memory material include, but are not limited to, chalcogenide element(s) compositions of the class of tellerium-germanium-antimony (TexGeySbz) material or GeSbTe alloys, although the scope of the present invention is not limited to just these.
• another phase change material may be used whose electrical properties (e.g. resistance, capacitance, etc.) may be changed through the application of energy such as, for example, light, heat, or electrical current.
• the pore 46 may be defined by a sidewall spacer 22 in one embodiment.
• the pore 46 and sidewall spacer 22 may be defined by an opening formed in a dielectric or insulating material 20.
• the material 20 may be an oxide, nitride, or any other insulating material.
• Below the pore 46 is a pair of lower electrodes including a relatively higher resistivity lower electrode 24 and a relatively lower resistivity lower electrode 26.
• the higher resistivity electrode 24 may be responsible for heating the adjacent portion of the phase change material 46 and, thus, may have a greater vertical extent.
• the lower resistivity electrode material 26 functions to distribute electrical current efficiently across the entire width of the higher resistivity electrode material 24.
• the conductor 30 may be cup- shaped in one embodiment of the present invention and may be filled with an insulator 28 which also surrounds the pedestal liner conductor 30.
• a nitride layer 32 may be penetrated by the pedestal liner conductor 30. The nitride layer
• the 32 may be positioned over an isolating layer 35 formed on a semiconductor substrate including a p+ region 38.
• the p+ region 38 may be adjacent a suicide contact region 34.
• an n-type silicon layer 40 Below the p+ region 38 is an n-type silicon layer 40.
• An n+ region 36 may be positioned between adjacent bitlines 14.
• Underneath the n-type silicon layer 40 is a p-type epitaxial (EPI) silicon layer 42 and a P++ type silicon substrate 44 in one embodiment of the present invention.
• EPI p-type epitaxial
• the resistivity of the relatively higher resistivity lower electrode 24 may be in the 1-500 mohm-cm, preferably 3-0.-1-00 mohm-cm range.
• the lower resistivity lower electrode 26 may have a resistivity in the 0.01-1.0 mohm-cm, preferably 0.05-0.15 mohm-cm range in one embodiment of the present invention.
• resistive materials that may be used as the electrodes 24 and 26 include silicon nitride and tantalum nitride.
• a processor-based system may include a processor 50 such as a general purpose or digital signal processor as two examples.
• the processor 50 may be coupled to the memory 10, for example, by a bus 52.
• a wireless interface 54 may be provided.
• the wireless interface 54 may include a transceiver or an antenna, to give two examples.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Semiconductor Memories (AREA)
• Inert Electrodes (AREA)
• Battery Electrode And Active Subsutance (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (2)

Family

ID=32506588

Family Applications (1)

Country Status (8)

Cited By (4)

Families Citing this family (48)

Family Cites Families (12)

• 2002
  • 2002-12-13 US US10/319,179 patent/US7049623B2/en not_active Expired - Lifetime
• 2003
  • 2003-04-28 KR KR1020057010563A patent/KR100669312B1/ko not_active Expired - Fee Related
  • 2003-04-28 AU AU2003225226A patent/AU2003225226A1/en not_active Abandoned
  • 2003-04-28 CN CN03825591.XA patent/CN1714461B/zh not_active Expired - Lifetime
  • 2003-04-28 WO PCT/US2003/013360 patent/WO2004055915A2/en not_active Ceased
  • 2003-04-28 JP JP2004560263A patent/JP4446891B2/ja not_active Expired - Fee Related
  • 2003-05-09 TW TW092112708A patent/TWI286750B/zh not_active IP Right Cessation
  • 2003-05-21 MY MYPI20031877A patent/MY135245A/en unknown
• 2005
  • 2005-11-10 US US11/270,909 patent/US7364937B2/en not_active Expired - Lifetime

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