摘要:
An electrically operated, directly overwritable, multibit, single-cell memory element. The memory element includes a volume of memory material which defines the single cell memory element. The memory material is characterized by: (1) a large dynamic range of electrical resistance values; and (2) the ability to be set at one of a plurality of resistance values within the dynamic range in response to selected electrical input signals so as to provide the single cell with multibit storage capabilities, and (3) the ability of at least a filamentary portion to be set, by the selected electrical singal to any resistance value in the dynamic range, regardless of the previous resistance value of the material. The memory element also includes a pair of spacedly disposed contacts for supplying the electrical input signal to set the memory material to a selected resistance value within the dynamic range. Each contact includes (1) a thin-film layer, preferably titanium cabonitride or titanium siliconitride, disposed adjacent to the memory material, used as a diffusion barrier to inhibit foreign material from entering the memory material, and (2) a thin-film layer, preferably a Ti--W alloy, disposed remote to the memory material, used to provide a barrier to aluminum electromigration, diffusion and providing an ohmic contact at the aluminum interface.
摘要:
A solid state, directly overwritable, electronic, non-volatile, high density, low cost, low energy, high speed, readily manufacturable, multibit single cell memory or control array based upon the novel switching characteristics provided by said unique class of semiconductor materials characterized by a large dynamic range of reversible Fermi level positions. The memory or control elements from which the array is fabricated exhibit orders of magnitude higher switching speeds at remarkably reduced energy levels. The novel memory elements of the instant invention are in turn characterized, inter alia, by numerous stable and non-volatile detectable configurations of local atomic and/or electrode order, which configurations can be selectively and repeatably accessed by electric input signals of yawing energy level. The memory elements are further characterized by enhanced stability, which stability is achieved through the use of compositional modulation of the semiconductor material from which the memory elements are fabricated.
摘要:
Disclosed herein is a solid state, directly overwritable, non-volatile, high density, low cost, low energy, high speed, readily manufacturable, single cell memory element having reduced switching current requirements and increased write/erase cycle life. The structurally modified memory element includes an electrical contact formed of amorphous silicon, either alone or in combination with a layer of amorphous carbon layer. The memory element exhibits orders of magnitude higher switching speeds at remarkably reduced switching energy levels. The novel memory elements of the instant invention are further characterized, inter alia, by at least two stable and non-volatile detectable configurations of local atomic and/or electronic order, which configurations can be selectively and repeatably accessed by electrical input signals of designated energies. The reduced switching current requirements and an increased write/erase cycle life are achieved by structurally modifying the electrical contact with the aforementioned layer of amorphous silicon.
摘要:
A solid state, directly overwritable, electronic, non-volatile, high density, low cost, low energy, high speed, readily manufacturable, multibit single cell memory based upon phenomenologically novel electrical switching characteristics provided by a unique class of semiconductor materials in unique configurations, which memory exhibits orders of magnitude higher switching speeds at remarkably reduced energy levels. The novel memory of the instant invention is characterized, inter alia, by numerous stable and truly non-volatile detectable configurations of local atomic and/or electronic order, which can be selectively and repeatably accessed by electrical input signals of varying pulse voltage and duration.
摘要:
Disclosed herein is a solid state, directly overwritable, non-volatile, high density, low cost, low energy, high speed, readily manufacturable, single cell memory element having reduced switching current requirements and an increased thermal stability of data retention. The memory element includes a volume of memory material which is a transition metal modified chalcogen. The transition metal may be selected from the group consisting of Nb, Pd, Pt and mixtures or alloys thereof. The memory material may further include at least one transition metal selected from the group consisting of Fe, Cr, Ni and mixtures or alloys thereof. The memory element exhibits orders of magnitude higher switching speeds at remarkably reduced switching energy levels. The novel memory element of the instant invention is in turn characterized, inter alia, by at least two stable and non-volatile detectable configurations of local atomic and/or electronic order, which configurations can be selectively and repeatably accessed by electrical input signals of designated energy levels. The memory elements are further characterized by enhanced thermal stability of data retention, which stability is achieved by elementally modifying Te--Ge--Sb semiconductor material from which previous memory elements were fabricated.
摘要:
The present invention comprises an electrically operated, directly overwritable, multibit, single-cell memory element. The memory element includes a volume of memory material which defines the single cell memory element. The memory material is characterized by: (1) a large dynamic range of electrical resistance values; and (2) the ability to be set at one of a plurality of resistance values within said dynamic range in response to selected electrical input signals so as to provide said single cell with multibit storage capabilities. The memory element also includes a pair of spacedly disposed contacts for supplying the electrical input signal to set the memory material to a selected resistance value within the dynamic range. At least a filamentary portion of the singIe cell memory element being setable, by the selected electrical signal to any resistance value in said dynamic range, regardless of the previous resistance value of said material. The memory element further includes a filamentary portion controlling means disposed between the volume of memory material and at least one of the spacedly disposed contacts. The controlling means defining the size and position of the filamentary portion during electrical formation of the memory element and limiting the size and confining the location of the filamentary portion during use of the memory element, thereby providing for a high current density within the filamentary portion of the single cell memory element upon input of a very low total current electrical signal to the spacedly disposed contacts.
摘要:
The present invention comprises an electrically operated, directly overwritable, multibit, single-cell memory element. The memory element includes a volume of memory material which defines the single cell memory element. The memory material is characterized by: (1) a large dynamic range of electrical resistance values; and (2) the ability to be set at one of a plurality of resistance values within said dynamic range in response to selected electrical input signals so as to provide said single cell with multibit storage capabilities. The memory element also includes a pair of spacedly disposed contacts for supplying the electrical input signal to set the memory material to a selected resistance value within the dynamic range. At least a filamentary portion of the single cell memory element being setable, by the selected electrical signal to any resistance value in said dynamic range, regardless of the previous resistance value of said material. The memory element further includes a filamentary portion controlling means disposed between the volume of memory material and at least one of the spacedly disposed contacts. The controlling means defining the size and position of the filamentary portion during electrical formation of the memory element and limiting the size and confining the location of the filamentary portion during use of the memory element, thereby providing for a high current density within the filamentary portion of the single cell memory element upon input of a very low total current electrical signal to the spacedly disposed contacts.
摘要:
A unique class of microcrystalline semiconductor materials which can be modulated, within a crystalline phase, to assume any one of a large dynamic range of different Fermi level positions while maintaining a substantially constant band gap over the entire range, even after a modulating field has been removed. A solid state, directly overwritable, electronic and optical, non-volatile, high density, low cost, low energy, high speed, readily manufacturable, multibit single cell memory based upon the novel switching characteristics provided by said unique class of semiconductor materials, which memory exhibits orders of magnitude higher switching speeds at remarkably reduced energy levels. The novel memory of the instant invention is in turn characterized, inter alia, by numerous stable and non-volatile detectable configurations of local atomic order, which configurations can be selectively and repeatably accessed by input signals of varying levels.
摘要:
A composite memory material comprising a mixture of active phase-change memory material and inactive dielectric material. The phase-change material includes one or more elements selected from the group consisting of Te, Se, Ge, Sb, Bi, Pb, Sn, As, S, Si, P, O and mixtures or alloys thereof. A single cell memory element comprising the aforementioned composite memory material, and a pair of spacedly disposed contacts.
摘要:
An electrically erasable phase change memory utilizing a stoichiometrically and volumetrically balanced phase change material in which both the switching times and the switching energies required for the transitions between the amorphous and the crystalline states are substantially reduced below those attainable with prior art electrically erasable phase change memories. One embodiment of the invention comprises an integrated circuit implementation of the memory in a high bit density configuration in which manufacturing costs are correspondingly reduced and performance parameters are further improved.