Method of programming a phase change memory and phase change memory device
AssigneesInstitut Polytechnique De Grenoble, Commissariat A L'energie Atomique Et Aux Ene Alt
InventorsQuentin HUBERT, Carine JAHAN
Life of this patent
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Abstract
A method for pre-programming a matrix of phase-change memory cells, including a phase-change material positioned between two conducting electrodes and able to be reversely electrically modified so as to vary the resistivity of the memory cell. A dielectric layer is provided with the memory cell having an original resistive state at the end of the memory cell production process. A pre-programming of the matrix is executed prior to mounting a component containing the matrix on a support. A breakdown voltage is applied to a selection of memory cells so that, for each one of the selected cells, the layer of the dielectric material breaks down to bring the cell from the original resistive state to a second resistive state.
Claims24
A method for pre-programming a matrix of phase-change memory cells, comprising a phase-change material positioned between two conducting electrodes, said phase-change material being able to be reversely electrically modified so as to vary the resistivity of the memory cell,
- characterized in that at least a dielectric layer is provided, which is positioned between the two conducting electrodes, with the memory cell having an original resistive state (original HRS) at the end of the memory cell production process,
- and in that a step of pre-programming the matrix is executed prior to a step of mounting a component containing said matrix onto a support, with the step of pre-programming comprising:
- applying a breakdown voltage to a selection of memory cells so that, for each one of the selected cells, the layer of the dielectric material breaks down to bring the cell from the original resistive state (original HRS) to a second resistive state (breakdown LRS), so that the cells which were, prior to mounting, in said original resistive state (original HRS) and in said second resistive state (breakdown LRS) are, after the step of mounting, in a third resistive state (mounting HRS) and in a fourth resistive state (mounting LRS), respectively, and in that the resistance of the cells in said third resistive state (mounting HRS) is at least twice higher than the resistance of the cells in said fourth resistive state (mounting LRS);
- and in that the following step is executed after mounting:
- reading the resistive state of all the cells in the matrix so as to identify the cells which are, after mounting, in said third resistive state (mounting HRS) and those which are in said fourth resistive state (mounting LRS).
A phase-change memory cell comprising a phase-change material and at least one electrode, characterized in that it comprises a dielectric layer positioned between the layer of phase-change material and the electrode, so that the memory cell initially is in an original resistive state (original HRS), with the memory cell being so configured as to enable selectively breaking down the dielectric layer so that the resistance of the memory cell is, after breakdown, in a second resistive state (breakdown LRS), so that the resistance of the cell in the original resistive state (original HRS) is at least twice higher than the resistance in the cell in said second resistive state (breakdown LRS), with the memory cell being so configured that the current flowing between the two conducting electrodes flows through the dielectric layer, with the dielectric layer being in contact with at least one among the layer of phase-change material and a heating element, characterized in that the contact surface between the dielectric layer and at least one among the layer of phase-change material and a heating element is smaller than the surface of the face of the dielectric layer with respect to at least one among the layer of phase-change material and a heating element.
Dependencies are inferred from the claim text.