US 12,414,307 B2
Cross-point magnetoresistive memory array including self-aligned dielectric spacers and method of making thereof
Jordan Katine, Mountain View, CA (US); and Lei Wan, San Jose, CA (US)
Assigned to Sandisk Technologies, Inc., Milpitas, CA (US)
Filed by SANDISK TECHNOLOGIES LLC, Addison, TX (US)
Filed on Mar. 14, 2022, as Appl. No. 17/654,777.
Prior Publication US 2023/0292528 A1, Sep. 14, 2023
Int. Cl. H10B 61/00 (2023.01); G11C 11/16 (2006.01); H10N 50/01 (2023.01); H10N 50/10 (2023.01); H10N 50/80 (2023.01); H10N 50/85 (2023.01)
CPC H10B 61/10 (2023.02) [G11C 11/1655 (2013.01); H10N 50/01 (2023.02); H10N 50/10 (2023.02); H10N 50/80 (2023.02); H10N 50/85 (2023.02); G11C 11/161 (2013.01); G11C 11/1659 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A memory array, comprising:
first electrically conductive lines laterally extending along a first horizontal direction and laterally spaced apart from each other along a second horizontal direction;
a two-dimensional array of selector-containing pillar structures located over the first electrically conductive lines and including a respective selector element;
a two-dimensional array of magnetic tunnel junction (MTJ) pillar structures located over the two-dimensional array of selector-containing pillar structures and including a respective magnetic tunnel junction (MTJ);
a two-dimensional array of tubular dielectric spacers laterally surrounding the two-dimensional array of MTJ pillar structures and having a respective outer sidewall having a bottom periphery that coincides with a top periphery of a sidewall of a respective underlying one of the selector-containing pillar structures; and
second electrically conductive lines laterally extending along the second horizontal direction and overlying the two-dimensional array of MTJ pillar structures;
wherein each selector-containing pillar structure of the two-dimensional array of selector-containing pillar structures comprises a vertical stack including a lower selector electrode, a non-Ohmic selector material plate overlying the lower selector electrode, and an upper selector electrode overlying the non-Ohmic selector material plate; and
wherein the upper selector electrode within each selector-containing pillar structure comprises:
a base portion having a first cylindrical surface segment, wherein a bottom periphery of the first cylindrical surface segment coincides with a periphery of a top surface of the non-Ohmic selector material plate; and
a pedestal portion overlying the base portion and having a second cylindrical surface segment that is laterally offset inward from a cylindrical vertical plane including the first cylindrical surface segment.