Phase change memory device and fabrication method thereof
AssigneesIndustrial Technology Research Institute, Powerchip Semiconductor Corp., Nanya Technology Corporation, ProMOS Technologies Inc., Winbond Electronics Corp.
InventorFrederick T Chen
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Abstract
A phase change memory device is disclosed. A second conductive spacer is under a first conductive spacer. A phase change layer comprises a first portion substantially parallel to the first and second conductive spacers and a second portion on top of the second conductive spacer, wherein the second conductive spacer is electrically connected to the first conductive spacer through the second portion of the phase change layer.
Claims12
A phase change memory device, comprising:
- a first dielectric layer comprising a first opening and a second opening under the first opening, wherein width of first opening is greater than the width of the second opening;
- a first conductive spacer on a sidewall of the first opening;
- a second conductive spacer on a sidewall of the second opening;
- a phase change layer at least covering sidewalls of the first and second conductive spacers and top of the second conductive spacer;
- and
- a second dielectric layer on the phase change layer,
- wherein each of the first conductive spacer and the second conductive spacer is L shaped and includes a vertical portion and a horizontal portion, the vertical portion is separated from the phase change layer by a dielectric spacer, and the horizontal portion contacts the phase change layer.
A method for forming a phase change memory device, comprising:
- forming a first dielectric layer on a bottom electrode;
- patterning the first dielectric layer to form a first opening;
- expanding the first opening;
- patterning the first dielectric layer to form a second opening under the first opening;
- forming a conductive-spacer layer on the first dielectric layer and in the first and second openings;
- forming a dielectric-spacer layer on the conductive-spacer layer;
- anisotropically etching the conductive-spacer layer and the dielectric-spacer layer to form a first conductive spacer on a sidewall of the first opening, a second conductive spacer on a sidewall of the second opening, a first dielectric spacer adjacent to the first conductive spacer and a second dielectric spacer adjacent to the second conductive spacer;
- conformally depositing a phase change layer in the first and second opening;
- and
- forming a second dielectric layer on the phase change layer,
- wherein each of the first conductive spacer and the second conductive spacer is L shaped and includes a vertical portion and a horizontal portion, the vertical portion is separated from the phase change layer by one of the first and second dielectric spacers, and the horizontal portion contacts the phase change layer.
Dependencies are inferred from the claim text.