A three dimensional (3D) memory array is disclosed. The 3D memory array may include an electrode plane and a memory material disposed through and coupled to the electrode plane. A memory cell included in the memory material is aligned in a same plane as the electrode plane, and the memory cell is configured to exhibit a first threshold voltage representative of a first logic state and a second threshold voltage representative of a second logic state. A conductive pillar is disposed through and coupled to the memory cell, wherein the conductive pillar and electrode plane are configured to provide a voltage across the memory cell to write a logic state to the memory cell. Methods to operate and to form the 3D memory array are disclosed.