Phase-change memory and fabrication method thereof
A phase-change memory is provided. The phase-change memory comprises a substrate. A first electrode is formed on the substrate. A circular or linear phase-change layer is electrically connected to the first electrode. A second electrode formed on the phase-change layer and electrically connected to the phase-change layer, wherein at least one of the first electrode and the second electrode comprises phase-change material.
1 . A phase-change memory element, comprising
a substrate;
a first electrode formed on the substrate;
a circular or linear phase-change layer electrically connected to the first electrode; and
a second electrode formed on the phase-change layer and electrically connected to the phase-change layer, wherein at least one of the first electrode and the second electrode comprises phase-change material.
2 . The phase-change memory element as claimed in claim 1 , wherein the phase-change material comprises chalcogenide.
3 . The phase-change memory element as claimed in claim 1 , wherein the dimension of the circular or linear phase-change layer is less than the resolution limit of photolithography process.
4 . The phase-change memory element as claimed in claim 1 , wherein the dimensions of phase-change layer from top to bottom are the same and the phase-change layer is essentiality perpendicular to the first electrode and second electrode.
5 . A method for fabricating phase-change memory elements, comprising:
providing a substrate;
forming a first electrode on the substrate;
forming a first dielectric layer on the first electrode;
patterning the first dielectric layer to form a dielectric pillar, wherein the top view of the dielectric pillar is circle or polygon;
conformally forming a phase-change material to cover the dielectric pillar and etching back the phase-change material to remove phase-change material on the top surface of the dielectric pillar and first electrode,
remaining a phase-change material spacer on the side walls of the dielectric pillar;
forming a second dielectric layer on the substrate and subjected to a back-etched, covering the sidewalls of the phase-change material spacer; and
forming a second electrode on the dielectric pillar and second dielectric layer electrically connect to the phase-change material.
6 . The method as claimed in claim 5 , wherein the phase-change material spacer has a width of 2 nm˜120 nm and a height of 1 mm˜200 nm.
7 . The method as claimed in claim 5 , wherein at least one of the first electrode and the second electrode comprises phase-change material.
8 . The method as claimed in claim 5 , wherein the top view of the phase-change material spacer is closed curve.
9 . The method as claimed in claim 5 , after forming the phase-change material spacer, further comprising:
patterning the phase-change material spacer to form a non-continuous phase-change material spacer.
10 . The method as claimed in claim 5 , after forming the second electrode, further comprising:
patterning the first electrode and the second electrode with the substrate acting as a etching-stop, and blanketly forming a third dielectric layer to surround the electrodes.
11 . The method as claimed in claim 5 , wherein the first electrode and the second electrode are patterned by different patterning processes.
12 . The method as claimed in claim 5 , wherein the dielectric pillar has a width of 20 nm˜500 nm.
13 . A method for fabricating phase-change memory element, comprising
providing a substrate;
forming a first electrode on the substrate;
forming a first dielectric layer on the first electrode;
patterning the first dielectric layer to form an opening, wherein the top view of the opening is circle or polygon;
conformally forming a phase-change material on the first dielectric layer to cover the opening and etching back the phase-change material to remain a phase-change material spacer on the side walls of the opening;
forming a second dielectric layer on the substrate and subjected to a back-etched, covering the sidewalls of the phase-change material spacer; and
forming a second electrode on the opening and the second dielectric layer to electrically connect to the phase-change material spacer.
14 . The method as claimed in claim 13 , wherein the phase-change material spacer has a width of 2 nm˜120 nm and a height of 1 nm˜200 nm.
15 . The method as claimed in claim 13 , wherein at least one of the first electrode and the second electrode comprises phase-change material.
16 . The method as claimed in claim 13 , wherein the top view of the phase-change material spacer is closed curve.
17 . The method as claimed in claim 13 , after forming the phase-change material spacer, further comprising:
patterning the phase-change material spacer to form a non-continuous phase-change material spacer.
18 . The method as claimed in claim 13 , after forming the second electrode, further comprising:
patterning the first electrode and the second electrode with the substrate acting as a etching-stop, and blanketly forming a third dielectric layer to surround the electrodes.
19 . The method as claimed in claim 13 , wherein the first electrode and the second electrode are patterned by different patterning processes.
20 . The method as claimed in claim 13 , wherein the opening has a width of 20 mm˜500 nm.