A method of making a memory array is provided that includes forming a layer over a substrate, forming features over the layer, forming sidewall spacers on each of the features, filling spaces between adjacent sidewall spacers with filler features, removing the sidewall spacers to leave the features and the filler features, and etching the layer using the features and the filler features as a mask to form pillar shaped nonvolatile memory cells. Numerous other aspects are provided.