Memory cell with alignment structure
View Patent ↗A memory cell that includes a memory element configured for switching from a first data state to a second data state by passage of current therethrough. The memory cell includes a top electrode and a bottom electrode for providing the current through the memory cell, and an alignment element positioned at least between the top electrode and the top surface of the memory element, the alignment element having an electrically conductive body tapering from the top electrode to the top surface of the memory element. Methods for forming the memory cell are also described.
1. A memory cell comprising:
a memory element configured for switching between various data states by passage of current therethrough, the memory element having a top surface and a bottom surface;
a top electrode and a bottom electrode for providing the current through the memory element; and
an alignment element positioned at least between the top electrode and the top surface of the memory element, the alignment element having an electrically conductive body tapering from the top electrode to the top surface of the memory element,
wherein the alignment element comprises:
a first alignment portion positioned between the top electrode and the top surface of the memory element, the first alignment portion having an electrically conductive body tapering from the top electrode to the top surface of the memory element; and
a second alignment portion positioned between the bottom electrode and the bottom surface of the memory element, the second alignment portion having an electrically conductive body tapering from the bottom electrode to the bottom surface of the memory element.
2. The memory cell of claim 1 , wherein the first alignment portion, memory cell and second alignment portion, combined, have a height and a width, with a ratio of the height to width being about 2:1 to about 10:1.
3. The memory cell of claim 1 wherein the first alignment portion and the second alignment portion are symmetrical around the memory cell.
4. The memory cell of claim 1 wherein the memory element has a width that is 10-20% of a maximum width of the alignment structure.
5. The memory cell of claim 1 further comprising a conformal oxide layer coating at least a portion of the memory element, the bottom electrode and the alignment element.
6. The memory cell of claim 1 wherein the memory element has a diameter of about 20 nm or less.
7. The memory cell of claim 6 wherein the memory element has a diameter of about 10 nm or less.
8. The memory cell of claim 1 wherein the alignment element comprises Cu, Al, W, Ta, or Cr.