Methods of forming an array of memory cells and memory cells that have pillars. Individual pillars can have a semiconductor post formed of a bulk semiconductor material and a sacrificial cap on the semiconductor post. Source regions can be between columns of the pillars, and gate lines extend along a column of pillars and are spaced apart from corresponding source regions. Each gate line surrounds a portion of the semiconductor posts along a column of pillars. The sacrificial cap structure can be selectively removed to thereby form self-aligned openings that expose a top portion of corresponding semiconductor posts. Individual drain contacts formed in the self-aligned openings are electrically connected to corresponding semiconductor posts.