A magnetic memory structure that includes a two-terminal resistive memory element electrically connected with a selector structure. The selector structure includes a semiconductor pillar structure formed on a semiconductor substrate. The selector structure is surrounded by a gate dielectric layer, and the semiconductor pillar structure and gate dielectric layer are surrounded by an electrically conductive gate structure. The semiconductor pillar has first and second dimensions in a plane parallel with the surface of the semiconductor substrate that are unequal with one another. The semiconductor pillar structure can have a cross-section parallel with the semiconductor substrate surface that is in the shape of a: rectangle; oval elongated polygon, etc. The length of the longer dimension can be adjusted to provide a desired amount of current though the semiconductor pillar structure to drive the two-terminal resistive memory element.