Method of manufacturing upwardly tapering heaters for phase change memories
View Patent ↗A substantially planar heater for a phase change memory may taper as it extends upwardly to contact a chalcogenide layer. As a result, the contact area between heater and chalcogenide is reduced. This reduced contact area can reduce power consumption in some embodiments.
1. A method comprising:
forming a heater between a phase change material and a substrate, wherein the heater has a width near the substrate greater than a width near the phase change material, wherein forming the heater comprises depositing a heater material on the substrate and on an end of a spacer material.
2. The method of claim 1 , wherein the spacer material comprises a tapered spacer material.
3. The method of claim 2 , wherein the end of the tapered spacer material has a triangular shape or a trapezoidal shape.
4. The method of claim 1 , further comprising forming a sacrificial material.
5. The method of claim 4 , further comprising:
depositing a spacer material; and
tapering sides of the spacer material to form the tapered spacer material.
6. The method of claim 5 , wherein depositing the heater material vertically from the substrate on an end of the tapered material comprises:
depositing the heater material on at least one of the sacrificial material and the tapered spacer material; and
removing the heater material from non-vertical surfaces of the at least one of the sacrificial material and the tapered spacer material to form the heater.
7. The method of claim 1 , further comprising providing the phase change material over the heater.
8. The method of claim 7 , further comprising providing a metal over the phase change material.
9. The method of claim 1 , wherein the phase change material comprises a chalcogenide film.
10. A method comprising:
forming a heater on a substrate, wherein the heater includes a concave surface along a vertical portion of the heater and wherein the heater has a first width near the substrate, and
depositing a phase change material on the heater, wherein the heater has a second width near the phase change material and wherein the phase change material is formed to have a third width near the heater that is approximately equal to the second width.
11. The method of claim 10 , wherein the vertical portion extends vertically from the substrate and a horizontal portion parallel to the substrate.
12. The method of claim 10 , wherein forming the heater comprises isotropically etching the vertical portion to form the concave surface along a vertical portion of the heater.
13. The method of claim 10 , further comprising depositing a metal on the phase change material.
14. The method of claim 12 , wherein the phase change material is narrowed during the isotropic etch.
15. The method of claim 12 , wherein selective properties of the isotropic etch prevent removal of the phase change material.
16. The method of claim 10 , wherein the second width is smaller than the first width.
17. A memory comprising:
a heater between a contact and a phase change material, wherein a surface area of the heater near the contact is greater than a surface area of the heater near the phase change material, wherein the heater has a triangular shape or a trapezoidal shape, wherein the heater is formed on the contact and on an end of a spacer material.
18. A memory comprising:
a heater between a contact and a phase change material, wherein the heater has opposed curvilinear side walls;
a chalcogenide material disposed on the heater; and
a cap disposed on the chalcogenide material.