Vertical transistor phase change memory
View Patent ↗Vertical transistor phase change memory and methods of processing phase change memory are described herein. One or more methods include forming a dielectric on at least a portion of a vertical transistor, forming an electrode on the dielectric, and forming a vertical strip of phase change material on a portion of a side of the electrode and on a portion of a side of the dielectric extending along the electrode and the dielectric into contact with the vertical transistor.
1. A method of processing a phase change memory cell, comprising:
forming a vertical strip of phase change material on a portion of a side of an electrode and on a portion of a side of a dielectric extending along the electrode and the dielectric into contact with a vertical transistor.
2. The method of claim 1 , wherein the method includes removing portions of the electrode and the dielectric, wherein removed portions are separated by two feature widths in a first direction.
3. The method of claim 2 , wherein the method includes removing portions of the electrode and the dielectric such that the two feature widths in the first direction span from a position above a first vertical transistor near a center point of the first vertical transistor to a position above a second vertical transistor adjacent to the first vertical transistor near a center point of the second vertical transistor.
4. The method of claim 1 , wherein forming the vertical strip of phase change material includes conformally forming the phase change material at least on top of the electrode, on the side of the electrode, on the side of the dielectric, and on top of the vertical transistor.
5. The method of claim 4 , wherein the method includes:
conformally forming an additional dielectric on the phase change material; and
removing material from a top of the vertical transistor to a depth equal to a thickness of the conformal formation of the additional dielectric plus a thickness of the conformal formation of the phase change material.
6. The method of claim 5 , wherein the method includes:
removing one feature width of material in the first direction between the portions separated by two feature widths to a height of the vertical transistor; and
removing portions of the phase change material between adjacent vertical transistors in a second direction.
7. A method of processing phase change memory cells, comprising:
forming a phase change material on, and in contact with, a dielectric and an electrode by a common plane, wherein the phase change material is on, and in contact with, a number of vertical transistors of an array of vertical transistors.
8. The method of claim 7 , wherein the method includes removing portions of the dielectric and the electrode, wherein the removed portions are separated by one feature width spans of remaining dielectric and electrode, and wherein the remaining dielectric and electrode span from a position above a particular vertical transistor to a position between the particular vertical transistor and an adjacent vertical transistor in a first direction.
9. The method of claim 7 , wherein forming the phase change material includes conformally forming the phase change material at least on top of the electrode, on the side of the electrode, on the side of the dielectric, and on top of the array of vertical transistors.
10. The method of claim 7 , wherein the method includes:
conformally forming an additional dielectric on the phase change material;
removing portions of the additional dielectric and the phase change material to a depth equal to a thickness of the formed additional dielectric and the phase change material; and
removing portions of the additional dielectric and phase change material extending from above a distal edge of a first vertical transistor to above a proximal edge of a second vertical transistor adjacent to the first vertical transistor in a second direction.
11. A method of processing phase change memory cells, comprising:
forming a spacer on an exposed pillar of a vertical transistor; and
forming a vertical line electrode between the spacer on the exposed pillar of the vertical transistor.
12. The method of claim 11 , wherein the method includes forming a phase change material on and in contact with the vertical line electrode, a dielectric, and a top electrode.
13. The method of claim 12 , wherein forming the phase change material includes:
forming the phase change material on a top surface of the vertical line electrode;
forming the phase change material on a side surface of the dielectric; and
forming the phase change material on a side surface of the top electrode.
14. The method of claim 12 , wherein forming the phase change material includes forming a vertical line of phase change material in a direction orthogonal to a direction of the vertical line electrode.
15. The method of claim 12 , wherein the method includes forming an additional dielectric on a side surface of the phase change material.
16. The method of claim 11 , wherein forming the spacer includes forming the spacer around an inner periphery of the exposed pillar of the vertical transistor.
17. A phase change memory cell, comprising:
a vertical transistor including a bottom electrode on a pillar;
a phase change material on a side surface of a top electrode, on a side surface of a dielectric, and on a top surface of the bottom electrode.
18. The phase change memory cell of claim 17 , wherein a width of the phase change material is less than a width of the top surface of the bottom electrode.
19. The phase change memory cell of claim 17 , wherein a width of the phase change material is less than a width of the side surface of the top electrode.
20. The phase change memory cell of claim 17 , wherein the phase change memory cell includes additional phase change material on an opposite side surface of the top electrode and on an opposite side surface of the dielectric.
21. The phase change memory cell of claim 17 , wherein the phase change memory cell includes an additional dielectric on a side surface of the phase change material opposite the side surface of the top electrode and opposite the side surface of the dielectric.
22. The phase change memory cell of claim 17 , wherein the phase change material includes an active region on the dielectric between the top electrode and the bottom electrode.
23. The phase change memory cell of claim 17 , wherein the phase change material extends from a top surface of the top electrode to a top surface of the bottom electrode.
24. A phase change memory cell, comprising:
a vertical transistor including a vertical line electrode;
a dielectric on a top surface of a portion of the vertical line electrode;
a top electrode on a top surface of the dielectric; and
a phase change material on a side surface of the top electrode.
25. The phase change memory cell of claim 24 , wherein the phase change material is in point contact with the vertical line electrode.
26. The phase change memory cell of claim 25 , wherein the phase change material includes an active region on the dielectric and on the point contact.
27. The phase change memory cell of claim 24 , wherein the phase change memory cell includes a spacer surrounding side surfaces of the vertical line electrode.