Phase change memory stack with treated sidewalls
Memory devices and methods for fabricating memory devices have been disclosed. One such method includes forming the memory stack out of a plurality of elements. An adhesion species is formed on at least one sidewall of the memory stack wherein the adhesion species has a gradient structure that results in the adhesion species intermixing with an element of the memory stack to terminate unsatisfied atomic bonds of the element. The gradient structure further comprises a film of the adhesion species on an outer surface of the at least one sidewall. A dielectric material is implanted into the film of the adhesion species to form a sidewall liner.
1. A method for fabricating a memory stack, the method comprising:
forming the memory stack out of a plurality of elements;
forming an adhesion species on at least one sidewall of the memory stack, the adhesion species having a gradient structure that results in the adhesion species intermixing with an element of the memory stack, the gradient structure comprising a film of the adhesion species on an outer surface of the at least one sidewall; and
implanting a dielectric material into the film.
2. The method of claim 1 , wherein forming the adhesion species comprises implanting the adhesion species into each sidewall of the memory stack and depositing a film of the adhesion species.
3. The method of claim 1 , wherein forming the adhesion species comprises performing a plasma immersion process and a deposition process.
4. The method of claim 3 , wherein performing the plasma immersion process comprises performing a plasma doping of boron into sidewalls of electrodes of the memory stack.
5. The method of claim 1 , wherein implanting the dielectric material into the film comprises implanting a nitride forming material into the film to form a BN x film sideliner.
6. The method of claim 1 , wherein forming the memory stack out of a plurality of elements comprises:
forming a word line material;
forming a first electrode material on the word line material;
forming a selector device material on the first electrode material;
forming a second electrode material on the selector device material;
forming a phase change material on the second electrode material; and
forming a third electrode material on the phase change material.
7. The method of claim 6 , wherein the first, second, and third electrode materials include carbon.
8. The method of claim 7 , wherein a boron adhesion species terminates unsatisfied atomic bonds of the carbon.
9. The method of claim 6 , wherein forming the word line material comprises forming a material including tungsten.
10. A method for fabricating a memory device comprising:
forming a plurality of memory stacks, each memory stack fabricated by:
forming a first carbon electrode on a word line material;
forming a selector device material on the first carbon electrode;
forming a second carbon electrode on the selector device material;
forming a phase change material on the second carbon electrode;
forming a third carbon electrode on the phase change material;
patterning and etching the selector device material, the first, second, and third carbon electrodes, and the phase change material to form the plurality of memory stacks; and
forming a gradient structured adhesion species on the sidewalls of the memory stack using an implant process and a deposition process, the gradient structure comprising a film of the adhesion species and an implanted adhesion species that intermixes with an element of the memory stack to terminate unsatisfied atomic bonds of the element; and
forming a liner material on the sidewalls of each memory stack by implanting a dielectric material into the film of the adhesion species.
11. The method of claim 10 , wherein forming the gradient structured adhesion species on the sidewalls comprises:
using a plasma doping process to implant a boron species; and
using a deposition process to form a boron film on the sidewall having the implanted boron species.
12. The method of claim 10 , wherein forming the liner material comprises forming a BN x liner material at least on the second carbon electrode.
13. The method of claim 10 , further comprising forming a dielectric fill material between pairs of the memory stacks.
14. The method of claim 10 , wherein forming the liner material comprises forming the liner material at a temperature of less than 390° C.