Memory device
AssigneesSTMicroelectronics S.r.l., Commissariat A L'energie Atomique Et Aux Energies Alternatives
InventorsPaolo Giuseppe CAPPELLETTI, Gabriele NAVARRO
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Abstract
A phase-change memory cell includes, in at least a first portion, a stack of at least one germanium layer covered by at least one layer made of a first alloy of germanium, antimony, and tellurium. In a programmed state, resulting from heating a portion of the stack to a sufficient temperature, portions of layers of germanium and of the first alloy form a second alloy made up of germanium, antimony, and tellurium, where the second alloy has a higher germanium concentration than the first alloy.
Claims26
A phase-change memory cell, comprising:
- an insulating layer including a resistive heating element;
- and
- a stack of a plurality of first layers made of a first alloy of germanium, antimony, and tellurium;
- each first layer in said stack of layers has different proportions of germanium, antimony, and tellurium.
A memory device, comprising:
- an insulating layer including a first resistive heating element associated with a first phase-change memory cell and a second resistive heating element associated with a second phase-change memory cell;
- a stack of a plurality of first layers made of a first alloy of germanium, antimony, and tellurium which extend over the first and second resistive heating elements;
- wherein each first layer in said stack of layers has different proportions of germanium, antimony, and tellurium;
- and
- wherein the stack includes a region in contact with the second resistive heating element that is made of a second alloy of germanium, antimony, and tellurium, wherein the second alloy has a higher germanium concentration than the first alloy.
A method of manufacturing a phase change memory cell, comprising:
- forming an insulating layer including a resistive heating element;
- forming a stack of layers, comprising:
- forming a first layer of a first alloy made of germanium, antimony, and tellurium on the insulating layer over the resistive heating element;
- and
- forming a second layer of the first alloy over the first layer;
- wherein the first and second layers of the first alloy have different proportions of germanium, antimony, and tellurium.
Dependencies are inferred from the claim text.